[Federal Register: July 2, 2002 (Volume 67, Number 127)]
[Rules and Regulations]               
[Page 44382-44392]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]



Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AF83

Endangered and Threatened Wildlife and Plants; Determination of 
Endangered Status for the Southern California Distinct Vertebrate 
Population Segment of the Mountain Yellow-Legged Frog (Rana muscosa)

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.


SUMMARY: We, the Fish and Wildlife Service (Service), determine 
endangered status for the southern California distinct vertebrate 
population segment (DPS) of the mountain yellow-legged frog (Rana 
muscosa) pursuant to the Endangered Species Act of 1973, as amended 
(Act). This rule implements the Federal protection and recovery 
provisions afforded by the Act for this DPS.

DATES: This rule is effective August 1, 2002.

ADDRESSES: Supporting documentation for this rulemaking is available 
for public inspection, by appointment, during normal business hours at 
the U.S. Fish and Wildlife Service, Carlsbad Fish and Wildlife Office, 
2730 Loker Avenue West, Carlsbad, CA 92008.

FOR FURTHER INFORMATION CONTACT: Jim Bartel, Field Supervisor, at the 
above address (telephone 760/431-9440 and facsimile 760/431-9618).



    The mountain yellow-legged frog is in the family of true frogs, 
Ranidae, which consists of frogs that are more closely tied to water 
bodies for breeding and foraging than other frog or toad species. 
Mountain yellow-legged frogs were originally described by Camp (1917) 
as a subspecies of Rana boylii. Zweifel (1955) demonstrated that frogs 
from the high Sierra Nevada and the mountains of southern California 
were somewhat similar to each other, yet were distinct from the rest of 
the R. boylii (= boylei) group. Since that time, most authors have 
treated the mountain yellow-legged frog as a full species, Rana 
muscosa, following Zweifel's treatment.
    Mountain yellow-legged frogs are moderately sized, about 40 to 80 
millimeters (mm) (1.5 to 3 inches (in)) from snout to urostyle (the 
pointed bone at the base of the backbone) (Zweifel 1955, Jennings and 
Hayes 1994). The skin pattern of the mountain yellow-legged frog is 
variable, ranging from discrete dark spots that can be few and large, 
to smaller and more numerous with a mixture of sizes and shapes, to 
irregular patches or a poorly defined network (Zweifel 1955). The body 
color is also variable, usually a mix of brown and yellow, but often 
with gray, red, or green-brown. Some individuals may be dark brown with 
little pattern (Jennings and Hayes 1994). Folds are present on each 
side of the back (dorsolateral folds), but usually are not prominent 
(Stebbins 1985). The throat is white or yellow, sometimes mottled with 
dark pigment (Zweifel 1955). The belly and undersurface of the hind 
limbs are yellow, which ranges in hue from pale lemon yellow to an 
intense sun yellow. Eye coloration consists of a gold-colored iris with 
a horizontal, black counter shading stripe (Jennings and Hayes 1994).
    The mountain yellow-legged frog is a near-endemic species to 
California (primarily restricted to California and a small area of 
Nevada), historically ranging in distribution from southern Plumas 
County in northern California to northern San Diego County in southern 
California. Within the range of the species, there are two major clades 
(a group of organisms that includes all descendants of one common 
ancestor) separated by a biogeographic break between the central and 
southern portions of the Sierra Nevada. These two clades can be further 
divided into four subgroups, the northern Sierra Nevada, central Sierra 
Nevada, southern Sierra Nevada, and southern California (Macey et al. 
2001). In the Sierra Nevada of California, the mountain yellow-legged 
frog ranges from northern Plumas County (G. Fellers in litt. 2000) to 
southern Tulare County (Jennings and Hayes 1994), at elevations mostly 
above 1,820 meters (m) (6,000 feet (ft)). The frogs of the southern 
Sierra Nevada are isolated from the frogs in the mountains of southern 
California by the Tehachapi Mountains and a distance of about 225 
kilometers (km) (140 miles (mi)).
    Mountain yellow-legged frogs were historically documented from 
approximately 166 localities in creeks and drainages in the mountains 
of southern California (Jennings and Hayes 1994). Of these, an 
estimated 164 localities were from creeks and drainages in the San 
Gabriel, Big Bear, and San Jacinto Mountains of Los Angeles, San 
Bernardino, and Riverside Counties. The two remaining occurrences were 
documented on Palomar Mountain in San Diego County and were considered 
to represent an isolated population (Zweifel 1955). Currently the 
mountain yellow-legged frog is known from only seven locations in 
southern California in portions of the San Gabriel, San Bernardino, and 
San Jacinto Mountains (Backlin et al. 2002).
    Localities of extant populations of mountain yellow-legged frogs in 
southern California are reported to range in elevation from 
approximately 370 m (1,200 ft) to 2,290 m (7,500 ft) (Stebbins 1985). 
Historical localities demonstrating the wide elevation range that 
mountain yellow-legged frogs inhabited in southern California include 
Eaton Canyon, Los Angeles County (370 m (1,220 ft)), and Bluff Lake, 
San Bernardino County (2,290 m (7,560 ft)).
    Southern California mountain yellow-legged frogs are diurnal 
(active during the daylight hours), highly aquatic frogs, occupying 
rocky and shaded streams with cool waters originating from springs and 
snowmelt. Water depth, persistence, and configuration (i.e., gently 
sloping shorelines and margins) appear to be important for mountain

[[Page 44383]]

yellow-legged frogs, allowing for shelter from predators along shores 
or in deeper waters, and habitat for breeding, foraging, egg-laying, 
thermoregulation (to regulate the body temperature through behavior), 
and overwintering (Jennings and Hayes 1994).
    Juvenile and adult mountain yellow-legged frogs feed primarily on 
small, streamside insects such as beetles, flies, ants, bees, and 
similar small insects (Jennings and Hayes 1994). The coldest winter 
months are spent in hibernation, probably underwater or in crevices in 
the streambanks. Mountain yellow-legged frogs emerge from overwintering 
sites in early spring and breeding soon follows. Breeding activity 
typically begins in April at lower elevations, to June or July at upper 
elevations and continues for approximately a month (Zweifel 1955). Egg 
masses vary in size from as few as 15 eggs to 350 eggs per mass 
(Vredenburg et al., in press), which is considered low, relative to a 
range of several hundred to several thousand for other true frogs such 
as the California red-legged frog (Rana aurora draytonii) (61 FR 25813, 
66 FR 14626). Egg masses are normally deposited in shallow waters where 
they may be attached to rocks, gravel, vegetation, or similar 
substrates (U. S. Forest Service (USFS) 2002). As larvae develop, they 
tend to gravitate towards warmer waters to elevate body temperatures 
(Bradford 1984) which may facilitate larval and metamorphic development 
by allowing for a higher metabolic rate. Even with this behavior, 
``larvae apparently must overwinter at least two times for 6 to 9 month 
intervals before attaining metamorphosis because the active season is 
short and the aquatic habitat maintains warm temperatures for only 
brief intervals'' (USFS 2002). Time to develop from fertilization to 
metamorphosis appears to be variable, ranging up to 3.5 years 
(Vredenburg et al., in press; Zweifel 1955), with reproductive maturity 
reached from 3 to 4 years following metamorphosis (Zweifel 1955). 
Little is known about adult longevity, but the species is presumed to 
be long-lived due to adult survivorship (i.e., observed survival of 
adults from year to year) (Mathews and Pope 1999, Pope 1999a in USFS 
2002). Further, Pope (1999a in USFS 2002) suggests that mountain 
yellow-legged frogs may have strong site fidelity for wintering and 
summer habitats.
    The decline of mountain yellow-legged frogs from more than 99 
percent of their previously documented range in southern California 
(Jennings and Hayes 1994) may be part of a well-known larger pattern of 
native ranid frog extirpations in the western United States (Hayes and 
Jennings 1986, Drost and Fellers 1996). Some of the western ranid frog 
species experiencing noticeable declines are the threatened California 
red-legged frog (61 FR 25813), the spotted frog (R. pretiosa and R. 
luteventris), the Cascades frog (R. cascadae), and the threatened 
Chiricahua leopard frog (R. chiricauhensis) (67 FR 40789). Nowhere have 
the declines been more pronounced than in southern California, where, 
in addition to declines in mountain yellow-legged frogs, the California 
red-legged frog has been reduced to a few small remnant populations (61 
FR 25813, 66 FR 14626) and the foothill yellow-legged frog (R. boylii) 
may be extirpated (Jennings and Hayes 1994).
    The mechanisms causing the declines of western ranid frogs are not 
well understood and are certain to vary somewhat among species. The two 
most common and well-supported hypotheses for widespread extirpation of 
western ranid frogs are: (1) Past habitat destruction related to 
activities such as logging, mining, and habitat conversions for water 
development, irrigated agriculture, and commercial development (Hayes 
and Jennings 1986, 61 FR 25813); and (2) non-native predators and 
competitors such as introduced trout and bullfrogs (Hayes and Jennings 
1986, Bradford 1989, Knapp 1996, Kupferberg 1997). However, in the case 
of the southern populations of mountain yellow-legged frogs, habitat 
destruction related to activities such as logging and commercial 
development does not appear to have been a significant factor in their 
precipitous decline because these activities are not prominent within 
mountain yellow-legged frog habitat in southern California. Overall, 
all of these factors, operating alone or in combination, may result in 
the direct extirpation of local populations of mountain yellow-legged 
frogs. Further, these factors may disrupt the natural cyclical 
population dynamics on the local and regional levels such that it may 
be difficult for populations to recover from localized impacts or 
    Other environmental factors that may adversely affect mountain 
yellow-legged frogs and other amphibian populations over a wide 
geographic range include pesticides (Sparling et al. 2001), certain 
pathogens (Blaustein et al. 1994, Fellers et al. 2001), ultraviolet-B 
(beyond the visible spectrum) radiation (Blaustein et al. 2001, Belden 
and Blaustein 2002), or a combination of the above factors (Kiesecker 
and Blaustein 1995, Blaustein et al. 2001, Kiesecker et al. 2001). 
However, these factors, their interactions, and their effects on the 
decline of amphibian populations are not well understood (Wake 1998, 
Fellers et al. 2001). We believe that these environmental factors are 
still operating, and unless moderated or reversed, a high probability 
exists that mountain yellow-legged frogs may become extirpated in 
southern California in the foreseeable future. Consequently, additional 
research on the effects of the factors on amphibian populations is 
necessary. To that end, the Department of the Interior (DOI) has 
supported an initiative to fund research on the causes of amphibian 
declines (USFWS 2000).
    Mountain yellow-legged frogs in southern California are found 
primarily on public land within the Angeles and San Bernardino National 
Forests. Therefore, the majority of mountain yellow-legged frog habitat 
is now protected or managed through management plans established for 
the Forests and sensitive species and habitat contained therein (refer 
to the Available Conservation Measures section for a further discussion 
of these measures). However, prior to the development of these 
management plans, dams or diversions were placed in many of the major 
streams flowing through the southern California mountains historically 
inhabited by mountain yellow-legged frogs. These dams and diversions 
alter natural hydrologic flow and may negatively impact mountain 
yellow-legged frog breeding and foraging habitat and further exacerbate 
the decline of populations in southern California.

Current Range and Status

    Surveys in 2000 and 2001 by the U.S. Geological Survey (USGS) found 
mountain yellow-legged frogs in five small streams in the San Gabriel 
Mountains, one stream, City Creek, a tributary of the Santa Ana River, 
in the San Bernardino Mountains, and one stream in the upper reaches of 
the San Jacinto River system in the San Jacinto Mountains (Backlin et 
al. 2002, USFS 2002). The results from the USGS surveys differ somewhat 
from the distribution of mountain yellow-legged frogs described in the 
proposed listing rule (64 FR 71714). Areas where mountain yellow-legged 
frogs were found during the surveys and adult population estimates for 
each area are described below. Areas where frog populations were 
reported in the proposed rule, but were not found during recent 
surveys, are also noted.
    San Gabriel Mountains, Angeles National Forest, San Bernardino 
County: Mountain yellow-legged frogs

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were detected at 5 of 17 San Gabriel Mountains sites surveyed in 2001: 
Bear Gulch, Devil's Canyon, Little Rock Creek, South Fork of Big Rock 
Creek, and Vincent Gulch. No frogs were detected at Alder Gulch during 
a summer 2001 survey, but they were reported at this site in 1995 
(Jennings 1995). Adult population estimates and 95 percent confidence 
intervals (CI) for the five sites were: 47 (95 percent CI = 22-108) for 
Bear Gulch, five (95 percent CI = 2-20) for Little Rock Creek, seven 
(95 percent CI = 1-7) for South Fork of Big Rock Creek, and 7 (95 
percent CI = 1-7) for Vincent Gulch (Backlin et al. 2002). No 
population estimate was made for Devil's Canyon, but four adults were 
found (Backlin et al. 2002).
    San Jacinto Mountains, San Bernardino National Forest, Riverside 
County: Only one site out of five surveyed in the San Jacinto Mountains 
in 2000 and 2001 was reported to be occupied (Backlin et al. 2002). One 
adult was found on Fuller Mill Creek during the five surveys conducted. 
No frogs were detected on the North Fork of the San Jacinto River from 
four surveys conducted in 2001, or in Dark Canyon during three surveys 
conducted in 2000 (Backlin et al. 2001). Mountain yellow-legged frogs 
were documented in Dark Canyon as recently as 1998 (Jennings 1999). 
Hall Canyon was not surveyed in 2000 and 2001. While frogs were not 
documented in this canyon during surveys in 1998 (Jennings 1999), eight 
adult mountain yellow-legged frogs and larvae were documented in 1995 
(Jennings 1995).
    San Bernardino Mountains, San Bernardino National Forest, Riverside 
County: Only one of 21 San Bernardino Mountains locations surveyed in 
2001 had mountain yellow-legged frogs (Backlin et al. 2002). This site, 
the East Fork of City Creek, has an estimated adult population size of 
13 (95 percent CI = 5-74) (Backlin et al. 2002). Similarly, the East 
Fork of City Creek was the only creek of the 15 locations surveyed in 
2000 that was documented as supporting mountain yellow-legged frogs 
(Backlin et al. 2002).
    Based on available recent information, it appears that mountain 
yellow-legged frogs have only been currently documented in seven creeks 
and drainages in the San Gabriel, San Jacinto, and San Bernardino 
Mountains of southern California, in contrast to the 166 documented 
historic localities. In 1994, Jennings and Hayes (1994) suggested that 
mountain yellow-legged frogs in the San Gabriel and San Jacinto 
Mountains (an estimated eight isolated localities) numbered fewer than 
100 adult frogs. Their estimate was based on a compilation of the 
results of visual surveys generally conducted on a single day, not on 
standard abundance estimation techniques. The current estimate of 
mountain yellow-legged frogs in southern California based on 
extrapolation from a mathematical formula is estimated to be 
approximately 79 adult frogs, not including direct observations in 
Devil's Canyon (4 adults in 2001) and Fuller Mill Creek (1 adult in 
2001), in which estimates were not calculated (Backlin et al. 2002). We 
acknowledge, however, that some creeks may have small populations that 
were not detected by recent 2000 and 2001 surveys efforts by Backlin et 
al. (2001; 2002).

Distinct Vertebrate Population Segment

    We evaluated populations of mountain yellow-legged frog according 
to the February 7, 1996, joint Service and National Marine Fisheries 
Service Policy Regarding the Recognition of Distinct Vertebrate 
Population Segments (61 FR 4722). Three elements are considered in a 
decision regarding the status of a possible DPS as endangered or 
threatened under the Act. These are applied similarly for addition to 
the lists of endangered and threatened wildlife and plants, 
reclassification, and removal from the lists and include: (1) 
Discreteness of the population segment in relation to the remainder of 
the species to which it belongs; (2) the significance of the population 
segment to the species to which it belongs; and (3) the population 
segment's conservation status in relation to the Act's standards for 
    Discreteness refers to the isolation of a population from other 
members of the species and is based on two criteria: (1) Marked 
separation from other populations of the same taxon resulting from 
physical, physiological, ecological, or behavioral factors, including 
genetic discontinuity; or (2) populations delimited by international 
    We determine significance either by the importance or contribution, 
or both, of a discrete population to the species throughout its range. 
Our policy lists four examples of factors that may be used to determine 
significance: (1) Persistence of the discrete population segment in an 
ecological setting unusual or unique for the taxon; (2) evidence that 
loss of the discrete population segment would result in a significant 
gap in the range of the taxon; (3) evidence that the discrete 
population segment represents the only surviving natural occurrence of 
the taxon that may be more abundant elsewhere as an introduced 
population outside its historic range; and (4) evidence that the 
discrete population segment differs markedly from other populations of 
the taxon in its genetic characteristics.
    If we determine that a population segment is discrete and 
significant, we evaluate it for endangered or threatened status based 
on the Act's standards. Endangered means the species is in danger of 
extinction throughout all or a significant portion of its range. 
Threatened means the species is likely to become endangered within the 
foreseeable future throughout all or a significant portion of its 
    Discreteness: The range of the mountain yellow-legged frog is 
divided by a natural geographic barrier, the Tehachapi Mountains, which 
geographically isolates frogs in the southern Sierra Nevada from those 
in the mountains of southern California. The distance of the geographic 
separation is about 225 km (140 mi). The geographic separation of the 
Sierra Nevada and southern California frogs was recognized in the 
earliest description of the species by Camp (1917), who treated frogs 
from the two localities as separate subspecies within the R. boylii 
group. He designated the Sierra Nevada frogs R. b. sierrae and the 
southern California frogs R. b. muscosa, based on geography and subtle 
morphological (outward appearance; structure and form) differences. 
Zweifel (1955) reevaluated the morphological evidence used by Camp and 
found it insufficient to warrant recognition of two subspecies.
    Using a limited sample size, Ziesmer (1997) analyzed the calls of 
Sierra Nevada (Alpine and Mariposa Counties) (n = 86 utterances) and 
southern California (San Jacinto Mountains, Riverside County) mountain 
yellow-legged frogs (n = 23 utterances). The calls of Sierra Nevada 
frogs differed from southern California frogs in pulse rate, harmonic 
structure, and dominant frequency (Ziesmer 1997). Ziesmer (1997) 
concluded that the differences in calls supported the hypothesis that 
mountain yellow-legged frogs from the Sierra Nevada and southern 
California are separate species.
    In addition, two different genetic analyses have been conducted 
that support the concept that mountain yellow-legged frog populations 
in southern California are different from those in the Sierra Nevada. 
As noted in the proposed listing rule (64 FR 71714), a previously 
unpublished allozyme study was used to compare mountain yellow-legged 
frogs for the central Sierra Nevada and southern California (Green in 
litt., 1993). He found a fairly significant genetic difference between 
the two populations, but without frogs

[[Page 44385]]

from the southern Sierra Nevada for comparison, it was not clear 
whether the difference reflected two ends of a cline (a character 
gradient), or distinct populations. Thus, due to the small sample 
sizes, the results were interpreted cautiously. More recently, a 
phylogenetic analysis of mitochondrial DNA sequences was performed on 
Rana muscosa throughout its distribution (Macey et al. 2001). 
Mitochondrial DNA sequences provide a more robust analysis of 
relationships than the allozymic data (Macey et al. 2001). Macey et al. 
(2001) found that eight populations of mountain yellow-legged frogs 
form two major clades separated by a biogeographic break in the Sierra 
Nevada. The break occurs between Kings Canyon National Park and a 
region slightly north of Yosemite National Park (Macey et al. 2001). 
The northern clade consists of populations from the northern and 
central Sierra Nevada, while the southern clade contains populations 
from the southern Sierra Nevada and the San Gabriel, San Jacinto, and 
San Bernardino Mountains in southern California. The two major clades, 
or groups, within R. muscosa are estimated to have diverged about 2.2 
million years ago (Macey et al. 2001).
    The two major clades each contained two subgroups, suggesting at 
least four evolutionarily distinct units within this taxon (Macey et 
al. 2001). Macey et al. (2001) found statistical support for 
evolutionarily distinct populations from the northern Sierra Nevada, 
central Sierra Nevada, southern Sierra Nevada, and southern California 
mountains (San Bernardino, Los Angeles, and Riverside counties). The 
southern Sierra Nevada and southern California subgroups are estimated 
to have diverged about 1.4 million years ago (Macey et al. 2001).
    The vocalization differences found by Ziesmer (1997) support the 
discreteness of southern California mountain yellow-legged frogs from 
the Sierra Nevada populations. The genetic study conducted by Macey et 
al. (2001) also strongly supports the conclusion that the population of 
mountain yellow-legged frogs in southern California is discrete. The 
results from these studies together with the geographic separation of 
the southern population from the rest of the populations in the Sierra 
Nevada satisfy the criterion of ``marked separation from other 
populations of the same taxon'' and qualify as discrete according to 
the Policy Regarding the Recognition of Distinct Vertebrate Population 
Segments (61 FR 4722).
    Significance: One of the most striking differences between Sierran 
and southern California mountain yellow-legged frogs is the ecological 
setting they each occupy. Zweifel (1955) observed that the frogs in 
southern California are typically found in steep gradient streams in 
the chaparral belt, even though they may range into small meadow 
streams at higher elevations. In contrast, Sierran frogs are most 
abundant in high elevation lakes and slow-moving portions of streams. 
Bradford's (1989) southern Sierra Nevada Mountain study site, for 
example, was in Sequoia and Kings Canyon National Parks, at high 
elevations between 2,910 to 3,430 m (9,600 to 11,319 ft). The rugged 
canyons of the arid mountain ranges of southern California bear little 
resemblance to the alpine lakes and streams of the Sierra Nevada. The 
different ecological settings between mountain yellow-legged frogs in 
southern California and those in the Sierra Nevada distinguish these 
populations from each other.
    The extinction of this southern group would be significant because 
it would substantially reduce the overall range to only the Sierra 
Nevada. The mountain yellow-legged frogs of southern California 
comprise the southern limit of the species' range, and the loss of the 
southern California frogs on the periphery of the species' range could 
have significant conservation implications. Peripheral populations may 
be genetically and morphologically divergent from central populations. 
As such, distinct traits found in peripheral populations may be crucial 
to the species, allowing adaptation to environmental change. Peripheral 
populations often are important for the survival and evolution of 
species and will often have high value for conservation (Lesica and 
Allendorf 1995).
    Based on the differences between the ecological settings for the 
mountain yellow-legged frog in southern California (steep gradient 
streams) and the Sierra Nevada (high elevation lakes and slow moving 
portions of streams), elevation, and the importance of the southern 
California population to the entire range of this species, the mountain 
yellow-legged frogs inhabiting the mountains of southern California 
meet the significance criteria under our Policy Regarding the 
Recognition of Distinct Vertebrate Population Segments (61 FR 4722).

Conservation Status

    Based on our determination that the southern California population 
of mountain yellow-legged frogs meets the first two criteria for a 
distinct vertebrate population segment per our policy, discreteness and 
significance, we must evaluate its conservation status and make a 
determination relative to the Act's standards for listing as endangered 
or threatened. Please refer to the Summary of Factors Affecting the 
Species for our discussion of the status of the species.

Previous Federal Action

    On July 13, 1995, we received a petition dated July 10, 1995, from 
D.C. Jasper Carlton of the Biodiversity Legal Foundation, Bonnie M. 
Dombrowski, and Michael C. Long to list as threatened or endangered the 
southern California population of the mountain yellow-legged frog 
pursuant to the Act. Accompanying the petition was supporting 
information related to the taxonomy, ecology, and past and present 
distribution of the species. We reviewed the petition, supporting 
documentation, and other information to determine if substantial 
information was available to indicate that the requested action may be 
warranted. On July 8, 1997, we published a 90-day administrative 
finding on the petition to list the southern California population of 
the mountain yellow-legged frog (62 FR 36481). In our finding, we 
discussed our determination that the petition presented substantial 
information indicating that listing of the species may be warranted and 
that we believed the southern California population to be a distinct 
vertebrate population segment.
    Once we determined that the petition presented substantial 
information, we commenced a status review pursuant to section 
4(b)(3)(A) of the Act. However, consistent with the applicable Listing 
Priority Guidances (62 FR 55268, 63 FR 25502), we worked on higher 
priority listing actions before completing the 12-month administrative 
finding and proposed listing rule on December 22, 1999, to list this 
DPS of the mountain yellow-legged frog as endangered (64 FR 71714). The 
processing of the 12-month administrative finding and the proposed 
listing rule conformed with our Listing Priority Guidance published in 
the Federal Register on October 22, 1999 (64 FR 57114).
    On May 19, 2000, we published a notice of reopening of the comment 
period in response to a request from the California Department of Fish 
and Game (CDFG) for additional time to obtain biological information 
regarding the mountain yellow-legged frog and to comment on the 
proposed rule (65 FR 31870). Due to limited resources and the need to 
undertake other, higher-priority listing actions, the Service was 
unable to make a final determination for this species within the 12-
month statutory timeframe provided by the Act. In August 2001, the 
Department of the

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Interior reached an agreement in principal with the Center for 
Biological Diversity, Southern Appalachian Biodiversity Project, and 
the California Native Plant Society on a timeframe to make final 
listing determinations for 14 species, including the mountain yellow-
legged frog (southern California DPS). The agreement was formalized in 
October 2001 (Center for Biological Diversity, et al. v. Norton, Civ. 
No. 01-2063 (JR) (D.D.C.)). The publication of the final rule to list 
the southern California distinct vertebrate population segment of the 
mountain yellow-legged frog complies with the terms of that court-
approved settlement agreement.
    Additionally, on February 10, 2000, we received a petition dated 
February 8, 2000, to list as endangered the Sierra Nevada population of 
the mountain yellow-legged frog as a distinct vertebrate population. 
The petition addresses the remainder of the entire species' range, in 
the Sierra Nevada from Tulare County, CA, in the south to Plumas 
County, CA, in the north. On October 12, 2000, we published an 
administrative 90-day finding indicating that the petition presented 
substantial information and that the petitioned action may be warranted 
(65 FR 60603), and we initiated a status review for the mountain 
yellow-legged frog. The results of this review will be addressed in our 
12-month administrative finding on the petitioned action.

Summary of Comments and Recommendations

    In the December 22, 1999, proposed rule (64 FR 71714), we requested 
all interested parties to submit factual reports or information that 
might contribute to development of this final rule during the 60-day 
public comment period which closed on February 22, 2000. We requested 
comments from appropriate Federal agencies, State agencies, county and 
city governments, scientific organizations, and other interested 
parties. We published public notices of the proposed rule in the Los 
Angeles Times in Los Angeles County on December 27, 1999, The Press-
Enterprise in Riverside County on December 29, 1999, and The Sun in San 
Bernardino County on December 30, 1999, inviting the general public to 
comment. On February 7, 2000, we received a request for a public 
hearing; however, at a later date the same individual provided comments 
on the proposed rule and retracted the request for a public hearing. On 
May 19, 2000, we reopened the public comment period for an additional 
30 days (65 FR 31870) to obtain biological information and to receive 
further comments on the proposed rule.
    During the two public comment periods, we received written comments 
from a total of 18 individuals or agencies. All commenters supported 
the listing of the mountain yellow-legged frog DPS in southern 
California, but several expressed concern over our discussion and 
analysis of the potential factors affecting the species.

Peer Review

    In accordance with our July 1, 1994, Interagency Cooperative Policy 
for Peer Review in Endangered Species Act Activities (59 FR 34270), we 
solicited the expert opinions of six independent specialists regarding 
pertinent scientific or commercial data and assumptions relating to the 
taxonomy, population status, and supporting biological and ecological 
information for the taxon under consideration for listing. The purpose 
of such review is to ensure that listing decisions are based on 
scientifically sound data, assumptions, and analyses, including input 
of appropriate experts and specialists. All six peer reviewers 
responded and supported the listing of this taxon. Information and 
suggestions provided by the reviewers were incorporated or addressed as 
    Comments on the proposed listing rule and our responses are either 
summarized below or directly incorporated into this final rule:
    Comment 1: A peer reviewer requested additional discussion of the 
potential effects of water projects in drainages where mountain yellow-
legged frogs occur.
    Our Response: Currently, we lack specific information to address 
adequately the effects of water projects in drainages on the mountain 
yellow-legged frog in this final rule. However, we recognize that these 
projects may affect the mountain yellow-legged frog and its habitat. We 
will continue to gather information and attempt to address this issue 
in the future.
    Comment 2: One peer reviewer noted our statement that all nine 
known populations of southern California mountain yellow-legged frog 
occur on USFS lands may not be true because Fuller Mill Creek flows 
through private property in the community of Pinewood.
    Our Response: We have made that correction in this final rule. As 
one of the conservation measures for the mountain yellow-legged frog, 
the USFS identified a portion of the private land along Fuller Mill 
Creek (approximately 24 hectares (ha) (60 acres (ac)) for acquisition 
(USFWS 2001). In January 2001, the USFS acquired 97 ha (240 ac) of 
private land along Fuller Mill Creek in Pinewood (Regelbrugge in litt. 
2002). While this land acquisition included the original 24 ha (60 ac) 
targeted, along with additional mountain yellow-legged frog habitat, 
portions of the creek that contain suitable, occupied habitat remain 
under private ownership.
    Comment 3: One commenter requested that future proposals of 
critical habitat undergo a public comment period similar to the 
proposed listing.
    Our Response: Pursuant to the Act and implementing regulations, we 
are required to solicit public comments on proposed rulemakings, 
including proposed critical habitat designations.
    Comment 4: One commenter responded that there is relatively little 
information on the life history of stream-dwelling mountain yellow-
legged frog populations, and our conclusion in the proposed listing 
rule that wherever rainbow trout (Oncorhynchus mykiss) and mountain 
yellow-legged frogs co-occur, trout are likely to eliminate mountain 
yellow-legged frogs was unsubstantiated, because the data was collected 
from high elevation lakes in the Sierra Nevada.
    Our Response: In our proposed listing rule, we stated that trout 
may keep populations of mountain yellow-legged frogs low and limit 
dispersal. Although all studies that have concluded trout negatively 
affect the distribution of mountain yellow-legged frogs were conducted 
on lakes and ponds in the Sierra Nevada (Bradford 1989, Knapp 1996, 
Knapp and Matthews 2000), the inference that trout in southern 
California streams would have the same or similar adverse effects on 
mountain yellow-legged frog populations is strong and should not be 
overlooked. In these studies, it was documented that nonnative trout 
may be the most severe threat affecting mountain yellow-legged frogs 
(Backlin et al. 2001) by predating larvae and metamorphs (Hays and 
Jennings 1986, Bradford 1989). Furthermore, research has shown adverse 
effects of trout on frog tadpoles in a stream-setting (Rattlesnake 
Creek) within the Santa Ynez Mountains (Cooper et al. 1986). Cooper et 
al. (1986) stated that their experiments showed that trout eliminated 
treefrog (Hyla spp.) tadpoles.
    We are currently funding a study through section 6 of the Act, to 
examine the natural history of the southern California DPS and 
interactions with trout.
    Comment 5: One commenter stated the proposed rule unnecessarily 

[[Page 44387]]

on potential public impacts, and was worried that as a result, the USFS 
would respond to the final listing with forest closures that are not 
warranted. The commenter noted human activities such as day use, hiking 
and camping were being singled out in the proposed rule.
    Our Response: Although we did not specifically identify 
recreational activities as a significant factor in the precipitous 
decline of the southern California DPS of mountain yellow-legged frog, 
the few remaining occurrences of this species in southern California 
are now at risk of extinction. Any activity that results in disturbance 
to the species or which may harm eggs, tadpoles or adult frogs could 
negatively affect the continued survival of this DPS. We have conferred 
with the USFS on their activities which may affect the mountain yellow-
legged frog and have identified actions to prevent impacts to the 
species (USFWS 2001). The small number of mountain yellow-legged frogs 
in southern California occur in a few stream reaches within the Angeles 
National Forest (ANF) and San Bernardino National Forest (SBNF). We 
believe that actions undertaken by the USFS to reduce impacts to this 
species on USFS lands in southern California will have a limited effect 
on current recreational activities within the Angeles and San 
Bernardino National Forests.
    Comment 6: One peer reviewer indicated that the recent genetic 
research conducted by Macey et al. (2001) suggested that the southern 
DPS of the mountain yellow-legged frog is in fact a separate species 
instead of a DPS, and that he had submitted a paper for review 
concerning this proposed taxonomic change.
    Our Response: In this final rule, we rely on the results of the 
recent genetic study by Macey et al. (2001) as further evidence that 
the southern populations of the mountain yellow-legged frog meet the 
policy definition of a distinct vertebrate population segment. While 
the results of this study provide substantial information concerning 
the taxonomy and evolutionary history of the mountain yellow-legged 
frog, Macey et al. (2001) do not suggest the four subgroups constitute 
separate species. We appreciate the information concerning the proposed 
taxonomic changes; and look forward to reviewing this new information 
following publication in a peer-reviewed journal.

Summary of Factors Affecting the Species

    Section 4 of the Endangered Species Act (16 U.S.C. 1531 et seq.) 
and the regulations (50 CFR part 424) that implement the listing 
provisions of the Act set forth the procedures for adding species to 
the Federal list of endangered and threatened species. A species may be 
determined to be endangered or threatened due to one or more of the 
five factors described in section 4(a)(1). These factors and their 
application to the southern California DPS of mountain yellow-legged 
frogs are discussed below:

A. The Present or Threatened Destruction, Modification, or Curtailment 
of Its Habitat or Range

    The seven remaining occurrences of the southern California DPS of 
mountain yellow-legged frog occur within three drainages; five are 
within a drainage in the San Gabriel Mountains, one population inhabits 
a drainage in the San Bernardino Mountains, and one is in the San 
Jacinto Mountains. Most of the known locations of this DPS occur on 
lands administered by the USFS. The extremely limited number and small 
size of the remaining populations makes this DPS of mountain yellow-
legged frog particularly vulnerable to extirpation resulting from 
localized habitat alteration or degradation, and stochastic (random, 
naturally occurring) events such as fire or drought (Backlin et al. 
    Alteration or degradation of habitat for this DPS within ANF and 
SBNF could result from recreational activities including hiking, 
mountain climbing, camping, swimming, stocking of trout for fishing, 
and suction dredge mining for gold; or other human-related impacts 
including release of toxic or hazardous materials into stream reaches 
inhabited by the DPS (Jennings 1995, Backlin et al. 2002, USFS 2002). 
In areas occupied by this DPS, human use in and along streams can 
disrupt the development, survivorship, and recruitment of eggs, larvae, 
and adult frogs (Jennings 1995; Stewart in litt. 1995), and can change 
the character of a stream and its bank and associated vegetation in 
ways that make whole sections of a stream less suitable for the 
    The following table identifies known recreational activities or 
other factors that may affect one or more of the remaining populations 
of the southern California DPS of mountain yellow-legged frog.

                                   Location of
       National Forest             population             Activity
ANF.........................  South Fork, Big Rock  Trout stocking.
ANF.........................  Little Rock Creek--   Trail use; mountain
                               Mojave.               climbing; vehicle
                                                     travel on Highway
ANF.........................  Bear Gulch--East      Suction dredge
                               Fork, San Gabriel.    mining for gold;
                                                     recreation (e.g.,
ANF.........................  Devil's Canyon--West  Recreation; trout
                               Fork, San Gabriel.    stocking.
ANF.........................  Vincent Gulch--East   None.
                               Fork, San Gabriel.
SBNF........................  East Fork City Creek- Vehicle travel on
                               -City Creek.          highway 330;
                                                     wildfire due to
                                                     buildup of fuels;
                                                     introduction of non-
                                                     resident trout.
SBNF........................  Fuller Mill Creek--   Picnicking; trout
                               Mill Creek.           stocking; wildfire

    Suction dredge mining for gold has occurred in a portion of the 
East Fork, San Gabriel River within the Sheep Mountain Wilderness Area. 
The dumping of trash and toxic materials (soap, motor oil, mercury) has 
also occurred in this area. (Jennings 1995). Some of the habitat 
effects of suction dredging on streams are described by Harvey (1986), 
who found that dredging may locally alter substrates and change habitat 
for fish and invertebrates. Consequently, disturbance to streambed 
substrates and water quality resulting from extensive suction dredging 
activity at or near a mountain yellow-legged frog breeding site could 
have harmful effects on eggs and developing larvae. Dumping of trash 
and toxic materials can degrade water quality, also with adverse 
effects on eggs and developing larvae.

B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    Numerous museum specimens from many localities document that 
mountain yellow-legged frogs from the southern DPS have been collected 
for scientific

[[Page 44388]]

purposes for decades (Jennings and Hayes 1994). Because the DPS has 
declined precipitously, resulting in a limited number of small 
populations, little scientific collecting of the southern DPS would 
likely be authorized. Collecting for scientific or recreational 
purposes, if it did occur, could seriously increase the probability of 
extirpation of any of the remaining populations, potentially reducing 
the ability of the DPS to survive and recover.

C. Disease or Predation

    Predation by introduced fish, primarily rainbow trout, is one of 
the best-documented causes of the decline of Sierran mountain yellow-
legged frogs. Careful study of the distributions of introduced trout 
and mountain yellow-legged frogs over several years has shown 
conclusively that introduced trout have had negative impacts on 
mountain yellow-legged frogs over much of the Sierra Nevada due to 
predation of tadpoles and other life stages (Bradford 1989, Knapp 1996, 
Knapp and Matthews 2000). Bradford (1989) and Bradford et al. (1993) 
concluded that introduced trout eliminate many populations of mountain 
yellow-legged frogs and the presence of trout in intervening streams 
sufficiently isolates other frog populations so that recolonization 
after stochastic local extirpations is essentially impossible. This 
mechanism is sufficient to explain the extirpation of Sierra Nevada 
mountain yellow-legged frogs from the majority of sites they once 
inhabited. Alone or in combination with other factors, introduced trout 
may have contributed to the widespread decline of the southern DPS as 
    Virtually all streams in the mountains of southern California 
contain populations of introduced rainbow trout, and until recently, 
trout were routinely released by California Department of Fish and Game 
in Dark Canyon and Fuller Mill Creek in the San Jacinto Mountains, and 
City Creek in the San Bernardino Mountains. Most of the other streams 
still occupied by mountain yellow-legged frogs have histories of trout 
introductions. However, the remaining frog occurrences in these streams 
are almost all in the small headwater sections where barriers restrict 
upstream movement of trout. While there have been no studies that 
specifically looked at the interaction between trout and stream-
dwelling mountain yellow-legged frogs in southern California, Cooper et 
al. (1986) found trout eliminated stream-dwelling treefrog (Hyla spp.) 
tadpoles in Rattlesnake Creek within the Santa Ynez Mountains. Wherever 
the two species co-occur, trout are likely to heavily impact mountain 
yellow-legged frog populations by eliminating or keeping populations 
low and limiting dispersal (Bradford 1989, Bradford et al. 1993). Knapp 
and Matthews (2000) suggested that mountain yellow-legged frog 
populations co-occurring with trout generally represent ``sink'' 
populations (a population in which the mortality rate exceeds the birth 
rate). Consequently, co-occurrence of mountain yellow-legged frogs and 
trout is insufficient evidence that trout have had relatively minor 
effects on frogs, because the persistence of these frog occurrences is 
likely dependent on immigration from source populations (Knapp and 
Matthews 2000). The widespread occurrence of introduced trout and 
continued releases in the mountains of southern California may make it 
very difficult to recover the DPS.
    Another introduced predator that could have effects on the DPS 
similar to those of the trout, but on a more limited scale, is the 
bullfrog (Rana catesbeiana). Bullfrogs have been listed among the 
threats to other western frogs (61 FR 25813, Kiesecker and Blaustein 
1998) and arroyo toads (59 FR 64859). Bullfrogs are now widespread in 
southern California and occur in many drainages formerly occupied by 
mountain yellow-legged frogs. The negative effects of bullfrogs on 
mountain yellow-legged frogs in the mountains of southern California 
are probably less widespread than those of introduced trout because 
there is less overlap in their occurrence. Any habitat alterations that 
are favorable to bullfrogs, however, will likely cause them to become 
locally abundant. In areas where mountain yellow-legged frogs occur, an 
increase of bullfrogs could further isolate the remaining populations; 
thereby potentially reducing the ability of the DPS to survive and 
    Bradford (1991) documented the loss of a Sierra Nevada population 
of mountain yellow-legged frogs due to the combined effect of ``red-
leg'' disease (caused by the freshwater bacterium Aeromonas hydrophila) 
and predation by Brewer's blackbirds (Euphagus cyanocephalus). Another 
pathogen that is generating concern among those who study amphibian 
declines is the chytrid fungus Batrachochytrium dendrobatidis. Chytrid 
fungus may be seriously affecting amphibians by attacking the 
mouthparts of tadpoles affecting their ability to feed. Chytrid fungus 
occurs in many places around the world, and has recently been 
discovered on larval and recently metamorphosed mountain yellow-legged 
frogs in the Sierra Nevada (Fellers et al. 2001). Because of the small 
and isolated nature of the remaining occurrences in southern 
California, disease could be significantly detrimental.

D. The Inadequacy of Existing Regulatory Mechanisms

    Existing regulatory mechanisms have not stopped the decline of 
mountain yellow-legged frogs in southern California. Existing 
regulatory mechanisms that could provide some protection for the 
mountain yellow-legged frog include: (1) State laws, including the 
California Endangered Species Act (CESA), California Environmental 
Quality Act (CEQA), and section 1603 of the California Fish and Game 
Code; (2) Federal laws and regulations including the National 
Environmental Policy Act (NEPA), the Endangered Species Act in those 
cases where this species occurs in habitat occupied by other listed 
species, Fish and Wildlife Coordination Act, and section 404 of the 
Federal Clean Water Act; and (3) local land use processes and 
    The State of California considers the mountain yellow-legged frog a 
species of special concern, but it is not listed as a threatened or 
endangered species under the CESA. Consequently, the species receives 
no protection under CESA. California Sport Fishing Regulations include 
the mountain yellow-legged frog as a protected species that may not be 
taken or possessed at any time except under special permit from the 
CDFG, however, the protection afforded by this regulation does not 
address the significant threats to the DPS presented by such factors as 
habitat alteration or predation by nonnative species.
    CEQA requires a full public disclosure of the potential 
environmental impact of proposed projects. The public agency with 
primary authority or jurisdiction over the project is designated as the 
lead agency, and is responsible for conducting a review of the project 
and consulting with other agencies concerned with resources affected by 
the project. Section 15065 of CEQA guidelines require a finding of 
significance if a project has the potential to ``reduce the number or 
restrict the range of a rare or endangered plant or animal.'' Species 
that are eligible for listing as rare, threatened, or endangered but 
are not so listed are given the same protection as those species that 
are officially listed with the State. Once significant impacts are

[[Page 44389]]

identified, the lead agency has the option to require mitigation for 
effects through changes in the project or to decide that overriding 
considerations make mitigation infeasible. In the latter case, projects 
may be approved that cause significant environmental damage, such as 
elimination of endangered species or their habitats. Protection of 
listed species through CEQA is, therefore, at the discretion of the 
lead agency involved. CEQA provides that, when overriding social and 
economic considerations can be demonstrated, project proposals may go 
forward, even in cases where the continued existence of the species may 
be threatened, or where adverse impacts are not mitigated to the point 
of insignificance.
    The arroyo toad (Bufo californicus), a federally listed endangered 
species, is present in the San Gabriel Mountains. Because the two 
species occupy different areas and habitats in the San Gabriel 
Mountains and the arroyo toads are not known to occur elsewhere in the 
limited range of the mountain yellow-legged frog, we believe there is 
limited benefit to the mountain yellow-legged frog from the presence of 
the arroyo toad.
    The Fish and Wildlife Coordination Act and section 404 of the Clean 
Water Act will afford some protection to mountain yellow-legged frogs 
where they occur in waters of the United States that require a permit 
from the U.S. Army Corps of Engineers (Corps). Under section 404 of the 
Clean Water Act, the Corps regulates the discharge of fill material 
into waters of the United States. Through the Fish and Wildlife 
Coordination Act, we may recommend discretionary conservation measures 
to avoid, minimize, and offset impacts to fish and wildlife resources 
resulting from a water development project authorized by the Corps. 
Section 404 regulations require that applicants obtain a nationwide, 
regional, or individual permit for projects that discharge fill 
material into waters of the United States.
    The U.S. Forest Service's Angeles and San Bernardino National 
Forests manage lands containing all known locations of mountain yellow-
legged frogs in southern California. The USFS has included mountain 
yellow-legged frogs on its Region 5 list of sensitive species as of 
June 8, 1998. The USFS has been formulating a conservation assessment 
and strategy for the mountain yellow-legged frog in southern California 
in a cooperative effort with other agencies, but this effort is still 
in progress (USFS 2002). As noted in the discussion of the factors 
above, the presence of introduced trout on USFS lands is believed to be 
a serious threat to the mountain yellow-legged frog. Additionally, 
because the DPS has been reduced to small isolated remnant populations, 
recreational activities (e.g., bathing, camping, hiking, etc.) 
occurring on USFS lands may threaten the remaining frogs. The perilous 
status of the mountain yellow-legged frog reflects the overall 
inability of existing CEQA, National Environmental Policy Act, and 
other Federal, State, and local ordinances and statutes to protect and 
provide for the conservation of this DPS.

E. Other Natural or Manmade Factors Affecting Its Continued Existence

    The southern California DPS of mountain yellow-legged frog is 
considered at high risk of extirpation because very few locations 
remain, the locations are isolated from one another, and each location 
likely contains only a small number of frogs. Few populations and 
restricted habitat make the southern California DPS of mountain yellow-
legged frog susceptible to extinction or extirpation from all or a 
portion of its range due to random events such as fire, flood or 
drought. In addition, small population size may increase the 
susceptibility of the remaining mountain yellow-legged frog populations 
in southern California to extirpation from random demographic, 
environmental and/or genetic events (Shaffer 1981, 1987; Lande 1988; 
Noss and Cooperrider 1994; Meffe and Carroll 1997, Primack 1998). 
Finally, disruption of source population and dispersal dynamics (e.g., 
source populations that provide individuals that can disperse to other 
populations or colonize new areas which assists in the stability and 
recovery of the species) may increase the risk of extinction of the 
southern California populations of the frog (Noss and Cooperrider 
1994). These effects are discussed briefly below.
    Unpredictable events such as fire could potentially eliminate 
entire populations of this DPS (Stewart in litt. 1995, Jennings 1995). 
Several of the remaining populations of mountain yellow-legged frog in 
southern California occur within areas where vegetation and fuel levels 
have increased. The increased fuel levels could lead to fires that burn 
more intensely, removing most of the vegetation which would affect the 
amount of available stream shade and could increase sedimentation 
within a stream channel due to exposed soils (USFS 2002).
    Mountain yellow-legged frog populations in the southern California 
DPS are also at risk from floods and drought. Unlike the lake 
environments utilized by the Sierra Nevada populations of the species, 
the streams inhabited by the southern California DPS flow through 
narrow canyons that provide little opportunity for off-channel refuge 
for the species during flood events (USFS 2002). Stewart (in litt. 
1995) believed that flooding during the winter of 1969 was a major 
factor in the disappearance of mountain yellow-legged frogs from Evey 
Canyon in the San Gabriel Mountains.
    Mountain yellow-legged frogs are almost always found in or 
immediately adjacent to water (USFS 2002). Periods of prolonged drought 
could have a significant effect on one or more of the remaining 
populations of this DPS as a result of reduced reproduction and 
reproductive success (i.e., mortality of eggs and tadpoles) (USFS 
    Demographic events that may put small populations at risk involve 
chance variation in age, sex ratios, and other population 
characteristics, which can change birth and death rates (Shaffer 1981, 
1987; Lande 1988; Noss and Cooperrider 1994; Meffe and Carroll 1997). A 
limited survey conducted by Jennings (1995) found skewed sex ratios in 
the populations of mountain yellow-legged frogs in the San Gabriel 
    Small, isolated populations are also vulnerable to genetic drift 
(random changes in gene frequencies) and inbreeding (mating among close 
relatives). Genetic drift and inbreeding may lead to reductions in the 
ability of individuals to survive and reproduce (i.e., reductions in 
fitness) in small populations. In addition, reduced genetic variation 
in small populations may make any species less able to successfully 
adapt to future environmental changes (Shaffer 1981, 1987; Noss and 
Cooperrider 1994, Primack 1998).
    Finally, we believe that the connectivity of populations within 
this DPS has been substantially reduced compared to the recent past. 
Loss of one or more of the remaining populations within the southern 
California DPS would cause the remaining populations to become even 
more isolated from one another, thereby reducing the likelihood of its 
long-term survival and recovery.
    We have evaluated the best available scientific and commercial 
information regarding the status of, and threats to, the southern 
California DPS of mountain yellow-legged frog in determining its 
eligibility for listing pursuant to the Act. Based on our evaluation, 
we determine that listing of the southern California DPS of

[[Page 44390]]

mountain yellow-legged frog as endangered, under the Act, is warranted 
and appropriate.

Critical Habitat

    Critical habitat is defined in section 3 of the Act as: (i) the 
specific areas within the geographical area occupied by a species, at 
the time it is listed in accordance with the provisions of section 4 of 
the Act, on which are found those physical or biological features (I) 
essential to the conservation of the species and (II) that may require 
special management considerations or protection, and (ii) specific 
areas outside the geographical area occupied by a species at the time 
it is listed, upon a determination by the Secretary that such areas are 
essential for the conservation of the species (16 U.S.C. 1532(5)). 
``Conservation'' means the use of all methods and procedures needed to 
bring an endangered or threatened species to the point at which 
protection under the Act is no longer necessary.
    Critical habitat designation directly affects only Federal agency 
actions through consultation under section 7(a)(2) of the Act. Section 
7(a)(2) requires Federal agencies to ensure that activities they 
authorize, fund, or carry out are not likely to jeopardize the 
continued existence of a listed species or destroy or adversely modify 
its critical habitat.
    Section 4(a)(3) of the Act, as amended, and implementing 
regulations (50 CFR 424.12) require that, to the maximum extent prudent 
and determinable, we designate critical habitat at the time the species 
is determined to be endangered or threatened. Our regulations (50 CFR 
424.12(a)(1)) state that the designation of critical habitat is not 
prudent when one or both of the following situations exist--(1) the 
species is threatened by taking or other human activity, and 
identification of critical habitat can be expected to increase the 
degree of threat to the species, or (2) such designation of critical 
habitat would not be beneficial to the species.
    Due to the small number and sizes of populations, the mountain 
yellow-legged frog is vulnerable to unrestricted collection, vandalism, 
or other disturbance. We are concerned that these threats might be 
exacerbated by the publication of critical habitat maps and further 
dissemination of location information. However, we have examined the 
evidence available for the mountain yellow-legged frog and have not 
found significant specific evidence of taking, vandalism, collection, 
or trade of this species or any similarly situated species. 
Consequently, consistent with applicable regulations (50 CFR 
424.12(a)(1)(i)) and recent case law, we do not expect that the 
identification of critical habitat will increase the degree of threat 
to this species of taking or other human activity.
    In the absence of a finding that critical habitat would increase 
threats to a species, if there are any benefits to critical habitat 
designation, then designating critical habitat is prudent. In the case 
of the southern California DPS of mountain yellow-legged frog, there 
may be some benefits to designation of critical habitat. The primary 
regulatory effect of critical habitat is the section 7 requirement that 
Federal agencies refrain from taking any action that destroys or 
adversely modifies critical habitat. While a critical habitat 
designation for habitat currently occupied by this species would not be 
likely to change the section 7 consultation outcome because an action 
that destroys or adversely modifies such critical habitat would also be 
likely to result in jeopardy to the species, there may be instances 
where section 7 consultation would be triggered only if critical 
habitat is designated. Examples could include unoccupied habitat or 
occupied habitat that may become unoccupied in the future. There may 
also be some educational or informational benefits to designating 
critical habitat. Therefore, we find that critical habitat is prudent 
for the southern California DPS of the mountain yellow-legged frog.
    However, the deferral of the critical habitat designation for this 
DPS of the mountain yellow-legged frog will allow us to concentrate our 
limited resources on higher priority critical habitat designations and 
other listing actions, while allowing us to put in place protections 
needed for the conservation of the southern California DPS of mountain 
yellow-legged frog without further delay. This is consistent with 
section 4(b)(6)(C)(i) of the Act, which states that final listing 
decisions may be issued without concurrent designation of critical 
habitat if it is essential to the conservation of the species that such 
determinations be promptly published. We will prepare a critical 
habitat designation for this species in the future at such time when 
our available resources allow it.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened under the Act include requirements for Federal protection, 
prohibitions against certain practices, and recovery actions. The Act 
provides for possible land acquisition/exchange and cooperation with 
the States. The protection required of Federal agencies and the 
prohibitions against certain activities involving listed species are 
discussed, in part, below. Listing of the southern California DPS of 
the mountain yellow-legged frog as endangered will provide for recovery 
planning including the development of a recovery plan if it will 
promote the conservation of the DPS. Such a plan will bring together 
both State and Federal efforts for the mountain yellow-legged frog's 
conservation. The plan will establish a framework for cooperation and 
coordination among agencies in conservation efforts. The plan will set 
recovery priorities and estimate costs of various tasks necessary to 
accomplish them. It will also describe site-specific management actions 
necessary to achieve conservation and survival of the southern 
California DPS of the mountain yellow-legged frog.
    Section 7(a) of the Act, as amended, requires Federal agencies to 
evaluate their actions with respect to any species that is proposed or 
listed as endangered or threatened and with respect to its critical 
habitat, if any is being designated. Regulations implementing this 
interagency cooperation provision of the Act are codified at 50 CFR 
part 402. Section 7(a)(4) requires Federal agencies to confer 
informally with the Service on any action that is likely to jeopardize 
the continued existence of a proposed species or result in destruction 
or adverse modification of its proposed critical habitat. If a species 
is listed subsequently, section 7(a)(2) requires Federal agencies to 
ensure that activities they authorize, fund, permit, or carry out are 
not likely to jeopardize the continued existence of such a species or 
to destroy or adversely modify its designated critical habitat. If a 
Federal action may affect a listed species or its designated critical 
habitat, the responsible Federal agency must enter into consultation 
with us.
    Federal agencies expected to have involvement with consultations 
under section 7 of the Act regarding the southern California DPS of 
mountain yellow-legged frog include the USFS through its management 
activities and the Corps through its permit authority under section 404 
of the Clean Water Act. These agencies either manage lands containing 
the DPS or authorize, fund, or otherwise conduct activities that may 
affect the DPS.
    In 2001, the Service issued its biological and conference opinions 
on the Land and Resource Management Plans (LRMP) for the four southern 
California National Forests (USFWS 2001) addressing activities on the

[[Page 44391]]

Angeles and San Bernardino National Forests. The southern California 
DPS of mountain yellow-legged frog, proposed for listing as endangered, 
was included in a conference opinion. Measures contained in a 
conference opinion are advisory in nature.
    Conservation recommendations for the southern California DPS of 
mountain yellow-legged frog included: (1) Installation of signage along 
trails adjacent to areas occupied by the DPS to encourage the public to 
remain on designated trails; (2) removal of picnic equipment or 
campsites (barbeque pits, picnic tables) adjacent to areas occupied by 
the DPS; (3) organization of workshops to educate campground permittees 
about this DPS of mountain yellow-legged frog; (4) acquisition of 
habitat for the DPS within private inholdings; (5) assignment of 
additional patrols to prevent illegal suction dredge mining within the 
Sheep Mountain Wilderness Area of Angeles National Forest; and (6) 
relocation of a trail adjacent to an area occupied by the DPS within 
Little Rock Canyon.
    The conference opinion addressing the southern DPS of mountain 
yellow-legged frog may be adopted as a biological opinion following the 
listing of this DPS under the Act, if we review the proposed action and 
determine there have been no significant changes in the action as 
planned or in the information used during the conference. If we 
determine the conference opinion may be adopted as the biological 
opinion, no further consultation pursuant to section 7 will be 
necessary, unless: (1) The amount of incidental take is exceeded; (2) 
new information reveals effects of the agency action that may affect 
the species or critical habitat in a manner and to an extent not 
considered in the conference opinion; (3) the agency action is 
subsequently modified in a manner that causes an effect to the species 
or critical habitat that was not considered in the conference opinion; 
or (4) a new species is listed or critical habitat designated that may 
be affected by the action.
    The Act and implementing regulations found at 50 CFR 17.21 set 
forth a series of general prohibitions and exceptions that apply to all 
endangered wildlife. These prohibitions under section 9 of the Act, in 
part, make it illegal for any person subject to the jurisdiction of the 
United States to take (including harass, harm, pursue, hunt, shoot, 
wound, kill, trap, capture, collect, or attempt any such conduct), 
import or export, transport in interstate or foreign commerce in the 
course of commercial activity, or sell or offer for sale in interstate 
or foreign commerce any listed species. It is also illegal to possess, 
sell, deliver, carry, transport, or ship any such wildlife that has 
been taken illegally. Certain exceptions apply to agents of the Service 
and State conservation agencies.
    It is the policy of the Service, published in the Federal Register 
on July 1, 1994 (59 FR 34272), to identify to the maximum extent 
practical at the time a species is listed those activities that would 
or would not constitute a violation of section 9 of the Act. The intent 
of this policy is to increase public awareness of the effect of listing 
a species pursuant to the Act on proposed and ongoing activities within 
the species' range. We believe the following actions would not likely 
result in a violation of section 9:
    Possession, delivery, or movement, including interstate transport 
and import into or export from the United States, involving no 
commercial activity, of dead specimens of this taxon that were 
collected prior to the date of publication in the Federal Register of 
the final regulation adding this taxon to the list of endangered 
    Activities we believe will result in a violation of section 9 of 
the Act include, but are not limited to:
    (1) Take of southern California mountain yellow-legged frogs 
without a permit, which includes harassing, harming, pursuing, hunting, 
shooting, wounding, killing, trapping, capturing, or collecting, or 
attempting any of these actions;
    (2) Possessing, selling, delivering, carrying, transporting, or 
shipping illegally taken mountain yellow-legged frogs;
    (3) Interstate and foreign commerce (commerce across State and 
international boundaries) and import/export (as discussed earlier in 
this section);
    (4) Introduction of non-native species that compete or hybridize 
with, or prey on, mountain yellow-legged frogs;
    (5) Destruction or alteration of mountain yellow-legged frog 
habitat by suction dredging, channelization, diversion, in-stream 
vehicle operation or rock removal, or other activities that result in 
the destruction or significant degradation of cover, channel stability, 
substrate composition, temperature, and habitat used by the species for 
foraging, cover, migration, and breeding; and
    (6) Discharging or dumping toxic chemicals, silt, or other 
pollutants into waters supporting mountain yellow-legged frogs by 
mining, or other developmental or land management activities that 
result in destruction or significant degradation of cover, channel 
stability, substrate composition, temperature, and habitat used by the 
species for foraging, cover, migration, and breeding.
    Questions regarding whether specific activities may constitute a 
violation of section 9 should be directed to the Field Supervisor, 
Carlsbad Fish and Wildlife Office (see FOR FURTHER INFORMATION 
CONTACT). Requests for copies of the regulations and inquiries 
regarding them may be addressed to the U.S. Fish and Wildlife Service, 
Ecological Services, Endangered Species Permits, 911 NE. 11th Avenue, 
Portland, OR 97232-4181 (Telephone 503/231-6241; FAX 503/231-6243).
    Permits may be issued to carry out otherwise prohibited activities 
involving endangered wildlife species under certain circumstances. 
Regulations governing these permits are at 50 CFR 17.22 and 17.23. Such 
permits are available for scientific purposes, to enhance the 
propagation or survival of the species, for incidental take in 
connection with otherwise lawful activities, and/or for economic 

National Environmental Policy Act

    We have determined that environmental assessments and environmental 
impact statements, as defined under the authority of the National 
Environmental Policy Act of 1969, need not be prepared in connection 
with regulations adopted pursuant to section 4(a) of the Endangered 
Species Act of 1973, as amended. A notice outlining the Service's 
reasons for this determination was published in the Federal Register on 
October 25, 1983 (48 FR 49244).

Paperwork Reduction Act

    This rule does not contain any collections of information that 
require Office of Management and Budget (OMB) approval under the 
Paperwork Reduction Act, 44 U.S.C. 3501 et seq. An information 
collection related to the rule pertaining to permits for endangered and 
threatened species has OMB approval and is assigned control number 
1018-0094, which expires July 31, 2004. This rule does not alter that 
information collection requirement. An agency may not conduct or 
sponsor, and a person is not required to respond to, a collection of 
information unless it displays a currently valid OMB control number.

References Cited

    A complete list of all references cited herein are available upon 
request from the Carlsbad Fish and Wildlife Office (see ADDRESSES).

[[Page 44392]]


    The primary author of this final rule is the Carlsbad Fish and 
Wildlife Office (see ADDRESSES).

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 
recordkeeping requirements, Transportation.

Regulation Promulgation

    For the reasons given in the preamble, we amend part 17, subchapter 
B of chapter I, title 50 of the Code of Federal Regulations, as set 
forth below:


    1. The authority citation for part 17 continues to read as follows:

    Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C. 
4201-4245; Pub. L. 99-625, 100 Stat. 3500, unless otherwise noted.

    2. Section 17.11(h) is amended by adding the following, in 
alphabetical order under AMPHIBIANS, to the List of Endangered and 
Threatened Wildlife to read as follows:

Sec. 17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

                        Species                                                    Vertebrate
--------------------------------------------------------                        population where                                  Critical     Special
                                                            Historic range       endangered or         Status      When listed    habitat       rules
           Common name                Scientific name                              threatened

                    *                  *                  *                  *                *                  *                  *

                    *                  *                  *                  *                *                  *                  *
Frog, mountain yellow-legged       Rana muscosa........  U.S.A. (California,  U.S.A., southern     E                       728           NA           NA
 (southern California DPS).                               Nevada).             California.

                    *                  *                  *                  *                *                  *                  *

    Dated: June 20, 2002.
Steve Williams,
Director, Fish and Wildlife Service.
[FR Doc. 02-16371 Filed 7-1-02; 8:45 am]