[Federal Register: April 20, 1999 (Volume 64, Number 75)]

[Rules and Regulations]               

[Page 19300-19309]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]





Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AF59


Endangered and Threatened Wildlife and Plants; Emergency Rule To 

List the Sierra Nevada Distinct Population Segment of California 

Bighorn Sheep as Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Emergency rule.


SUMMARY: We, the U.S. Fish and Wildlife Service (Service), exercise our 

authority to emergency list the Sierra Nevada distinct population 

segment of California bighorn sheep (Ovis canadensis californiana), 

occupying the Sierra Nevada of California, as endangered under the 

Endangered Species Act of 1973, as amended (Act). The Sierra Nevada 

bighorn sheep is known from five disjunct subpopulations along the 

eastern escarpment of the Sierra Nevada totaling about 100 animals.

    All five subpopulations are very small and are imminently 

threatened by mountain lion (Puma concolor) predation and disease. 

Because these threats constitute an emergency posing a significant risk 

to the well-being of the Sierra Nevada bighorn sheep, we find that 

emergency listing is necessary. This emergency rule provides Federal 

protection pursuant to the Act for this species for a period of 240 

days. A proposed rule to list the Sierra Nevada bighorn sheep as 

endangered is published concurrently with this emergency rule in this 

same issue of the Federal Register in the proposed rule section.

DATES: This emergency rule becomes effective immediately upon 

publication and expires December 16, 1999.

ADDRESSES: The complete file for this rule is available for inspection, 

by appointment, during normal business hours at the U.S. Fish and 

Wildlife Service, Ventura Fish and Wildlife Office, 2493 Portola Rd. 

Suite B, Ventura, California 93003.

FOR FURTHER INFORMATION CONTACT: Carl Benz, at the address listed above 

(telephone 805/644-1766; facsimile 805/644-3958).


    The bighorn sheep (Ovis canadensis) is a large mammal (family 

Bovidae) originally described by Shaw in 1804 (Wilson and Reeder 1993). 

Several subspecies of bighorn sheep have been recognized on the basis 

of geography and differences in skull measurements (Cowan 1940; 

Buechner 1960). These subspecies of bighorn sheep, as described in 

these early works, include O. c. cremnobates (Peninsular bighorn 

sheep), O. c. nelsoni (Nelson bighorn sheep), O. c. mexicana (Mexican 

bighorn sheep), O. c. weemsi (Weems bighorn sheep), O. c. californiana 

(California bighorn sheep), and O. c. canadensis (Rocky Mountain 

bighorn sheep). However, recent genetic studies question the validity 

of some of these subspecies and suggest a need to re-evaluate overall 

bighorn sheep taxonomy. For example, Sierra Nevada bighorn sheep appear 

to be more closely related to desert bighorn sheep than the O. c. 

californiana found in British Columbia (Ramey 1991, 1993). Regardless, 

the Sierra Nevada bighorn sheep meets our criteria for consideration as 

a distinct vertebrate population segment (as discussed below) and is 

treated as such in this emergency rule.

    The historical range of the Sierra Nevada bighorn sheep (Ovis 

canadensis californiana) includes the eastern slope of the Sierra 

Nevada, and, for at least one subpopulation, a portion of the western 

slope, from Sonora Pass in Mono County south to Walker Pass in Kern 

County, a total distance of about 346 kilometers (km) (215 miles (mi)) 

(Jones 1950; Wehausen 1979, 1980). By the turn of the century, about 10 

out of 20 historical subpopulations survived. The number dropped to 

five subpopulations at mid-century, and down to two subpopulations in 

the 1970s, near Mount Baxter and Mount Williamson in Inyo County 

(Wehauser 1979). Currently, five subpopulations of Sierra Nevada 

bighorn sheep occur at Lee Vining Canyon, Wheeler Crest, Mount Baxter, 

Mount Williamson, and Mount Langley in Mono and Inyo counties, three of 

which are reintroduced subpopulations established from sheep obtained 

from the Mount Baxter subpopulation from 1979 to 1986 (Wehausen et al. 


    The Sierra Nevada bighorn sheep is similar in appearance to other 

desert associated bighorn sheep. The species' pelage shows a great deal 

of color variation, ranging from almost white to dark brown, with a 

white rump. Males and females have permanent horns; the horns are 

massive and coiled in males, and are smaller and not coiled in females 

(Jones 1950; Buechner 1960). As the animals age, their horns become 

rough and scarred with age, and will vary in color from yellowish-brown 

to dark brown. In comparison to many other desert bighorn sheep, the 

horns of the Sierra Nevada bighorn sheep are generally more divergent 

as they coil out from the base (Wehausen 1983). Adult male sheep stand 

up to a meter (m) (3 feet (ft)) tall at the shoulder; males weigh up to 

99 kilograms (kg) (220 pounds (lbs)) and females 63 kg (140 lbs) 

(Buechner 1960).

    The current and historical habitat of the Sierra Nevada bighorn 

sheep is almost entirely on public land managed by the U.S. Forest 

Service (USFS), Bureau of Land Management (BLM), and National Park 

Service (NPS). The Sierra Nevada is located along the eastern boundary 

of California, and peaks vary

[[Page 19301]]

in elevation from 1825 to 2425 (m) (6000 to 8000 ft) in the north, to 

over 4300 m (14,000 ft) in the south adjacent to Owens Valley, and then 

drop rapidly in elevation in the southern extreme end of the range 

(Wehausen 1980). Most precipitation, in the form of snow, occurs from 

October through April (Wehausen 1980).

    Sierra Nevada bighorn sheep inhabit the alpine and subalpine zones 

during the summer, using open slopes where the land is rough, rocky, 

sparsely vegetated and characterized by steep slopes and canyons 

(Wehausen 1980: Sierra Nevada Bighorn Sheep Interagency Advisory Group 

(Advisory Group) 1997). Most of these sheep live between 3,050 and 

4,270 m (10,000 and 14,000 ft) in elevation in summer (John Wehausen, 

University of California, White Mountain Research Station, pers. comm. 

1999). In winter, they occupy high, windswept ridges, or migrate to the 

lower elevation sagebrush-steppe habitat as low as 1,460 m (4,800 ft) 

to escape deep winter snows and find more nutritious forage. Bighorn 

sheep tend to exhibit a preference for south-facing slopes in the 

winter (Wehausen 1980). Lambing areas are on safe steep, rocky slopes. 

They prefer open terrain where they are better able to see predators. 

For these reasons, they usually avoid forests and thick brush if 

possible (J. Wehausen, pers. comm. 1999).

    Bighorn sheep are primarily diurnal, and their daily activity show 

some predictable patterns that consists of feeding and resting periods 

(Jones 1950). Bighorn sheep are primarily grazers, however, they may 

browse woody vegetation when it is growing and very nutritious. They 

are opportunistic feeders selecting the most nutritious diet from what 

is available. Plants consumed include varying mixtures of graminoids 

(grasses), browse (shoots, twigs, and leaves of trees and shrubs), and 

herbaceous plants depending on season and location (Wehausen 1980). In 

a study of the Mount Baxter and Mount Williamson subpopulations, 

Wehausen (1980) found that grass, mainly Stipa speciosa (perennial 

needlegrass), is the primary diet item in winter. As spring green-up 

progresses, the bighorn sheep shift from grass to a more varied browse 

diet, which includes Ephedra viridis (Mormon tea), Eriogonum 

fasciculatum (California buckwheat), and Purshia species (bitterbrush).

    Sierra Nevada bighorn sheep are gregarious, with group size and 

composition varying with gender and from season to season. Spatial 

segregation of males and females occurs outside the mating season, with 

males more than 2 years old living apart from females and younger males 

for most of the year (Jones 1950; Cowan and Geist 1971; Wehausen 1980). 

Ewes generally remain all their lives in the same band into which they 

were born (Cowan and Geist 1971). During the winter, Sierra Nevada 

bighorn sheep concentrate in those areas suitable for wintering, 

preferably Great Basin habitat (sagebrush steppe) at the very base of 

the eastern escarpment. Subpopulation size can number more than 100 

sheep, including rams (this was observed at a time when the population 

size was larger than it is currently) (J. Wehausen, pers. comm. 1999). 

By summer, these subpopulations decrease in size as more habitat 

becomes available. Breeding takes place in the fall, generally in 

November (Cowan and Geist 1971). Single births are the norm for North 

American wild sheep, but twinning is known to occur (Wehausen 1980). 

Gestation is about 6 months (Cowan and Geist 1971).

    Lambing occurs between late April to early July, with most lambs 

born in May or June (Wehausen 1980, 1996). Ewes with newborn lambs live 

solitarily for a short period before joining nursery groups that 

average about six sheep. Ewes and lambs frequently occupy steep terrain 

that provides a diversity of slopes and exposures for escape cover. 

Lambs are precocious, and within a day or so, climb almost as well as 

the ewes. Lambs are able to eat vegetation within 2 weeks of their 

birth and are weaned between 1 and 7 months of age. By their second 

spring, they are independent of their mothers. Female lambs stay with 

ewes indefinitely and may attain sexual maturity during the second year 

of life. Male lambs, depending upon physical condition, may also attain 

sexual maturity during the second year of life (Cowan and Geist 1971). 

Average lifespan is 9 to 11 years in both sexes, though some rams are 

known to have lived 12 to 14 years (Cowan and Geist 1971; Wehausen 


Distinct Vertebrate Population Segment

    Recent analyses of bighorn sheep genetics and morphometrics (size 

and shape of body parts) suggest reevaluation of the taxonomy of Sierra 

Nevada bighorn sheep (Ovis canadensis californiana) is necessary (Ramey 

1991, 1993,1995; Wehausen and Ramey 1993, 1998). A recent analysis of 

the taxonomy of bighorn sheep using morphometrics (e.g., size and shape 

of skull components) failed to support the current taxonomy (Wehausen 

and Ramey 1993). However, this and other research (Ramey 1993) support 

taxonomic distinction of the Sierra Nevada bighorn sheep relative to 

other nearby regions.

    The biological evidence supports recognition of Sierra Nevada 

bighorn sheep as a distinct vertebrate population segment for purposes 

of listing, as defined in our February 7, 1996, Policy Regarding the 

Recognition of Distinct Vertebrate Population Segments (61 FR 4722). 

The definition of ``species'' in section 3(16) of the Endangered 

Species Act of 1973, as amended (Act) (16 U.S.C. 1531 et seq.) includes 

``any distinct population segment of any species of vertebrate fish or 

wildlife which interbreeds when mature.'' For a population to be listed 

under the Act as a distinct vertebrate population segment, three 

elements are considered--(1) the 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 listing (i.e., is the population 

segment endangered or threatened?) (61 FR 4722).

    The distinct population segment (DPS) of bighorn sheep in the 

Sierra Nevada is discrete in relation to the remainder of the species 

as a whole. This DPS is geographically isolated and separate from other 

California bighorn sheep. There is no mixing of this population with 

other bighorn sheep, and this is supported by evaluation of the 

population's genetic variability and morphometric analysis of skull and 

horn variation (Ramey 1993, 1995; Wehausen and Ramey 1993, 1994; 

Wehausen and Ramey 1999 (in review)). Researchers suggest that all 

other populations of O. c. californiana be reassigned to other 

subspecies, leaving O. c. californiana (i.e., the DPS that is the 

subject of this rule) only in the central and southern Sierra Nevada 

(Ramey 1993, 1995; Wehausen and Ramey 1993, 1994; Wehausen and Ramey 

1999 (in review)).

    Sierra Nevada bighorn sheep DPS is biologically and ecologically 

significant to the species to which it belongs in that it constitutes 

the only population of California bighorn sheep inhabiting the Sierra 

Nevada. This DPS extends from Sonora Pass to Walker Pass, and spans 

approximately 346 km (215 mi) of contiguous suitable habitat in the 

United States. The loss of Sierra Nevada bighorn sheep would result in 

the total extirpation of bighorn sheep from the Sierra Nevada in 


[[Page 19302]]

Status and Distribution

    Historically, bighorn sheep populations occurred along and east of 

the Sierra Nevada crest from Sonora Pass (Mono County) south to Walker 

Pass (Olancha Peak) (Kern County) (Jones 1950; Wehausen 1979). Sheep 

apparently occurred wherever appropriate rocky terrain and winter range 

existed. With some exception, most of the populations wintered on the 

east side of the Sierra Nevada and spent summers near the crest 

(Wehausen 1979).

    Subpopulations of Sierra Nevada bighorn sheep probably began 

declining with the influx of gold miners to the Sierra Nevada in the 

mid-1880s, and those losses have continued through the 1900s (Wehausen 

1988). By the 1970s, only 2 subpopulations of Sierra Nevada bighorn 

sheep, those near Mount Baxter and Mount Williamson in Inyo County, are 

known to have survived (Wehausen 1979). Specific causes for the 

declines are unknown. Market hunting may have been a contributing 

factor as evidenced by menus from historic mining towns such as Bodie, 

which included bighorn sheep (Advisory Group 1997). However, with the 

introduction of domestic sheep in the 1860s and 1870s, wild sheep are 

known to have died in large numbers in several areas from disease 

contracted from domestic livestock (Jones 1950; Buechner 1960). Large 

numbers of domestic sheep were grazed seasonally in the Owens Valley 

and Sierra Nevada prior to the turn of the century (Wehausen 1988), and 

disease is believed to be the factor most responsible for the 

disappearance of bighorn sheep subpopulations in the Sierra Nevada. 

Jones (1950) suggested that scabies was responsible for a die-off in 

the 1870s on the Great Western Divide. Experiments have confirmed that 

bacterial pneumonia (Pasteurella species), carried normally by domestic 

sheep, can be fatal to bighorn sheep (Foreyt and Jessup 1982).

    By 1979, only 220 sheep were known to exist in the Mount Baxter 

subpopulation, and 30 in the Mount Williamson subpopulation (Wehausen 

1979). Conservation efforts by several Federal and State agencies from 

1970 to 1988 were aimed at expanding the distribution of Sierra Nevada 

bighorn sheep by translocating sheep back into historical habitat. 

Sheep were obtained from the Mount Baxter subpopulation and 

transplanted to three historic locations. Consequently, Sierra Nevada 

bighorn sheep now occur in five subpopulations in Mono and Inyo 

counties: Lee Vining Canyon, Wheeler Crest, Mount Baxter, Mount 

Williamson, and Mount Langley. The Sierra Nevada bighorn sheep 

population reached a high of about 310 in 1985-86. Subsequently, 

population surveys have documented a declining trend (J. Wehausen, 

pers. comm. 1999).

    The following table best represents the total Sierra Nevada bighorn 

sheep population over various time periods. These totals represent the 

numbers of sheep emerging from winter in each of these years, and best 

document the status of the population by incorporating winter 

mortality, especially of lambs born the previous year. These totals are 

not absolute values; numbers have been rounded to the nearest five (J. 

Wehausen, pers. comm. 1999). The continuing decline of the Sierra 

Nevada bighorn sheep has been attributed to a combination of the direct 

and indirect effects of predation (Wehausen 1996).

  Table 1. Sierra Nevada Bighorn Sheep Population Numbers, by Year (J.

                       Wehausen, Pers. Comm. 1999)


                                                    Number of     Total

                       Year                        populations    sheep


1978.............................................           2        250

1985.............................................           4        310

1995.............................................           5        100

1996.............................................           5        110

1997.............................................           5        130

1998.............................................           5        100


Previous Federal Action

    In our September 18, 1985, Notice of Review, we designated the 

Sierra Nevada bighorn sheep as a category 2 candidate and solicited 

status information (50 FR 37958). Category 2 candidates were those taxa 

for which we had information indicating that proposing to list as 

endangered or threatened was possibly appropriate, but for which 

sufficient data on biological vulnerability and threats were not 

currently available to support a proposed rule. Category 1 taxa were 

those taxa for which we had sufficient information on file to support 

issuance of proposed listing rules. In our January 6, 1989 (54 FR 554), 

and November 21, 1991 (56 FR 58804), Notices of Review, we retained the 

Sierra Nevada bighorn sheep in category 2. Beginning with our February 

28, 1996, Notice of Review (61 FR 235), we discontinued the designation 

of multiple categories of candidates, and we now consider only taxa 

that meet the definition of former category 1 as candidates for 

listing. At this point, the Sierra Nevada bighorn sheep was identified 

as a species of concern.

    The processing of this emergency rule conforms with our listing 

priority guidance published in the Federal Register on May 8, 1998 (63 

FR 25502). This guidance clarifies the order in which we will process 

rulemakings giving highest priority (Tier 1) to processing emergency 

listings and second highest priority (Tier 2) to resolving the listing 

status of outstanding proposed listings, resolving the conservation 

status of candidate species, processing administrative findings on 

petitions to add species to the lists or reclassify species from 

threatened to endangered status, and delisting or reclassifying 

actions. The lowest priority actions, processing critical habitat 

designations, are in Tier 3. This emergency rule constitutes a Tier 1 


Summary of Factors Affecting the Species

    After a thorough review and consideration of all information 

available, we have determined that the Sierra Nevada bighorn sheep 

warrants classification as an endangered distinct population segment. 

We followed procedures found at section 4 of the Act and regulations 

(50 CFR part 424) promulgated to implement the listing provisions of 

the Act. We may determine a species 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 Sierra Nevada bighorn sheep 

distinct population segment (Ovis canadensis californiana), are as 


    A. The present or threatened destruction, modification, or 

curtailment of its habitat or range. Habitat throughout the historic 

range of Sierra Nevada bighorn sheep remains essentially intact; the 

habitat is neither fragmented nor degraded. However, by 1900, about 

half of the Sierra Nevada bighorn sheep populations were lost, most 

likely because of introduction of diseases by domestic livestock, and 

illegal hunting (Advisory Group 1997). Beginning in 1979, animals from 

the Mount Baxter subpopulation were translocated to reestablish 

subpopulations in Lee Vining Canyon, Wheeler Crest, and Mount Langley 

in Mono and Inyo counties (Advisory Group 1997). Currently, Sierra 

Nevada bighorn sheep are limited to five subpopulations. Almost all of 

the historical and current habitat is administered by either the USFS, 

BLM, or NPS. Some small parcels of inholdings within the species' range 

are owned by the Los Angeles Department

[[Page 19303]]

of Water and Power. Also, there are some patented mining claims in 

bighorn sheep habitat, but the total acreage is small.

    B. Overutilization for commercial, recreational, scientific, or 

educational purposes. During the period of the California gold rush 

(starting about 1849), hunting to supply food for mining towns may have 

played a role in the decline of the population (Wehausen 1988). Besides 

being sought as food, Sierra Nevada bighorn sheep were also killed by 

sheepmen who considered wild sheep as competitors for forage with 

domestic sheep. The decimation of several wildlife species in the late 

1800s prompted California to pass legislation providing protection to 

deer, elk, pronghorn antelope, and bighorn sheep (Jones 1950; Wehausen 


    Commercial and recreational hunting of Sierra Nevada bighorn sheep 

is not permitted under State law. There is no evidence that other 

commercial, recreational, scientific, or educational activities are 

currently a threat. Poaching does not appear to be a problem at this 


    C. Disease or predation. Disease is believed to have been the major 

contributing factor responsible for the precipitous decline of Sierra 

Nevada bighorn sheep starting in the late 1800s (Foreyt and Jessup 


    Bighorn sheep are host to a number of internal and external 

parasites, including ticks, lice, mites, tapeworms, roundworms, and 

lungworms. Most of the time, parasites are present in relatively low 

numbers and have little effect on individual sheep and populations 

(Cowan and Geist 1971).

    Cattle were first introduced into the Sierra Nevada in 1860s but 

were replaced with domestic sheep that could graze more extensively 

over the rugged terrain (Wehausen et al. 1987; Wehausen 1988). Large 

numbers of domestic sheep were grazed seasonally in the Sierra Nevada 

prior to the turn of the century, and the domestic sheep would use the 

same ranges as the wild sheep, occasionally coming into direct contact 

with them. Both domestic sheep and cattle can act as disease 

reservoirs. Scabies, most likely contracted from domestic sheep, caused 

a major decline of bighorn sheep in California in the 1870s to the 

1890s and caused catastrophic die-offs in other parts of their range 

(Buechner 1960). A die-off of bighorn sheep in the 1870s on the Great 

Western Divide (Mineral King area of Sequoia National Park) was 

attributed to scabies, presumably contracted from domestic sheep (Jones 


    Die-offs from pneumonia contracted from domestic sheep is another 

important cause of losses. In 1988, a strain of pneumonia, apparently 

contracted from domestic sheep, wiped out a reintroduced herd of 

bighorn sheep in Modoc County. Native bighorn sheep cannot tolerate 

strains of respiratory bacteria, such as Pasteurella species, carried 

normally by domestic sheep and close contact with domestic animals 

results in transmission of disease and subsequent deaths of the exposed 

animals (Foreyt and Jessup 1982). Bighorn sheep can also develop 

pneumonia independent of contact with domestic sheep. Lungworms of the 

genus Protostrongylus are often an important contributor to the 

pneumonia disease process in some situations (J. Wehausen, pers. comm. 

1999). Lungworms are carried by an intermediate host snail, which is 

ingested by a sheep as it is grazing. Lungworm often exists in a 

population, but usually doesn't cause a problem. However, if the sheep 

are stressed in some way, they may develop bacterial pneumonia, which 

is complicated by lungworm infestation. Bacterial pneumonia is usually 

a sign of weakness caused by some other agent such as a virus, 

parasite, poor nutrition, predation, human disturbance, or 

environmental or behavioral stress that lowers the animal's resistance 

to disease (Wehausen 1979; Foreyt and Jessup 1982). Bighorn sheep in 

the Sierra Nevada carry Protostrongylus species (lungworms), but the 

parasite loads have been low, and there has been no evidence of any 

clinical signs of disease or disease transmission (Wehausen 1979; 

Richard Perloff, Inyo National Forest, pers. comm. 1999).

    Currently, domestic sheep grazing allotments are permitted by the 

U.S. Forest Service in areas adjacent to Sierra Nevada bighorn sheep 

subpopulations. Domestic sheep occasionally escape the allotments and 

wander into bighorn sheep areas, sometimes coming into direct contact 

with bighorn sheep (Advisory Group 1997). For example, in 1995, 22 

domestic sheep that were permitted on USFS land wandered away from the 

main band and were later found in Yosemite National Park, after 

crossing through occupied bighorn sheep habitat (Advisory Group 1997; 

Bonny Pritchard, Inyo National Forest, pers. comm. 1999; R. Perloff, 

pers. comm. 1999). Other stray domestic sheep, in smaller numbers, have 

been known to wander up the road in Lee Vining Canyon into bighorn 

sheep habitat (B. Pritchard, pers. comm. 1999). Based on available 

information, and given the susceptibility of bighorn sheep to 

introduced pathogens, disease will continue to pose a significant and 

underlying threat to the survival of Sierra Nevada bighorn sheep until 

the potential for contact with domestic sheep is eliminated.

    Predators such as coyote (Canis latrans), bobcat (Lynx rufus), 

mountain lion, gray fox (Urocyon cinereoargenteus), golden eagle 

(Aquila chrysaetos), and free-roaming domestic dogs prey upon bighorn 

sheep (Jones 1950; Cowan and Geist 1971). Predation generally has an 

insignificant effect except on small populations such as the Sierra 

Nevada bighorn sheep. Coyotes are the most abundant large predator 

sympatric (occurring in the same area) with bighorn sheep populations 

(Bleich 1999) and are known to have killed young Sierra Nevada bighorn 

sheep (Vernon Bleich, California Department of Fish and Game, pers. 

comm. 1999). In the late 1980s, mountain lion predation of Sierra 

Nevada bighorn sheep increased throughout their range (Wehausen 1996). 

This trend has continued into the 1990s, as evidenced by Table 1.

    Predation by mountain lion probably was a natural occurrence and 

part of the natural balance of this ecosystem. From 1907 to 1963, the 

State provided a bounty on mountain lions; the State also hired 

professional lion hunters for many years. The bounty most likely kept 

the mountain lion population reduced such that bighorn sheep predation 

was rare and insignificant. Between 1963 and 1968, mountain lions were 

managed as a nongame and nonprotected mammal, and take was not 

regulated. From 1969 to 1972, lions were re-classified as game animals. 

A moratorium on mountain lion hunting began in 1972 and lion numbers 

likely increased. In 1986, the species was again classified as a game 

animal, but the California Department of Fish and Game (CDFG) hunting 

recommendations were challenged in court in 1987 and 1988 (Torres et 

al. 1996). In 1990, a State-wide ballot initiative (Proposition 117) 

passed into law prohibiting the killing of mountain lions except if 

humans or their pets or livestock are threatened. Another ballot 

measure, Proposition 197, which would have modified current law 

regarding mountain lion management failed to pass in 1996, largely 

because of the public's concern that the change may allow mountain lion 

hunting (Torres et al. 1996). With the removal of the ability to 

control the mountain lion population, lion predation has become a 

significant limiting factor for the Sierra Nevada bighorn sheep.

[[Page 19304]]

    The increased presence of mountain lions appears to have changed 

Sierra Nevada bighorn sheep winter habitat use patterns. Wehausen 

(1996) looked at mountain lion predation in two bighorn sheep 

subpopulations, one in the Granite Mountains of the eastern Mojave 

Desert, and the other was the Mount Baxter subpopulation in the Sierra 

Nevada. He found that the lions reduced the subpopulation in the 

Granite Mountains to eight ewes between 1989 and 1991, and held it at 

that level for 3 years, after which lion predation decreased and the 

bighorn sheep subpopulation increased at 15 percent per year for 3 

years. All the mortality in that subpopulation was attributed to 

mountain lion predation. The Mount Baxter bighorn sheep subpopulation 

abandoned its winter ranges, presumably due to mountain lion predation. 

Forty-nine sheep were killed by lions on their winter range between 

1976 and 1988 out of an average subpopulation size of 127 sheep. These 

mortalities from mountain lion predation represented 80 percent of all 

mortality on the winter range, and 71 percent for all ranges used. 

There is also evidence that many of the bighorn sheep killed were 

prime-aged animals (J. Wehausen, pers. comm. 1999).

    The bighorn sheep on Mount Baxter moved to higher elevations 

possibly to evade lions. By avoiding the lower terrain and higher 

quality forage present during the spring, sheep emerge from the winter 

months in poorer condition. Consequences from the change in habitat use 

resulted in a decline in the Mount Baxter subpopulation due to 

decreased lamb survival, because lambs were born later and died in 

higher elevations during the winter. This may have also been the case 

with the Lee Vining subpopulation decline, when the bighorn sheep ran 

out of fat reserves at a time when they should have been replenishing 

their reserves with highly nutritious forage from low elevation winter 

ranges. Because of the winter habitat shift by the bighorn sheep, the 

Mount Baxter subpopulation has declined significantly. With the large 

decline of bighorn sheep on Mount Baxter, the total population of 

Sierra Nevada bighorn sheep has now dropped below what existed when the 

restoration program began in 1979 (Wehausen 1996; Advisory Group 1997). 

In a 1996 survey on Mount Williamson, there was no evidence of groups 

of sheep, and this subpopulation was the last one found using its low-

elevation winter range in 1986. Mountain lion predation may have led to 

the extirpation of this subpopulation, one of the last two native 

subpopulations of Sierra Nevada bighorn sheep (Wehausen 1996; J. 

Wehausen, pers. comm. 1999).

    The Sierra Nevada bighorn sheep restoration program used the Mount 

Baxter subpopulation as the source of reintroduction stock from 1979 to 

1988. The three reintroduced subpopulations at Lee Vining Canyon, 

Wheeler Mountain, and Mount Langley all suffered from mountain lion 

predation shortly after translocation of sheep (Wehausen 1996). The Lee 

Vining Canyon subpopulation lost a number of sheep to mountain lion 

predation, threatening the success of the reintroduction effort (Chow 

1991, cited by Wehausen (1996)). The subpopulation was supplemented 

with additional sheep and the State removed one mountain lion each year 

for 3 years, which helped reverse the decline of this subpopulation 

(Bleich et al. 1991 and Chow 1991, cited by Wehausen (1996)). Also, 

because domestic sheep are preyed upon by mountain lions, livestock 

operators who have a Federal permit to graze their sheep on USFS land 

can get a depredation permit from the State, and have the U.S. 

Department of Agriculture, Wildlife Services, remove the mountain lion. 

The Lee Vining Canyon subpopulation occurs in the general area where 

domestic sheep are permitted, and has benefitted for the last 4 or 5 

years from the removal of two to three mountain lions per year that 

were preying on domestic sheep (B. Pritchard, pers. comm. 1999).

    D. The inadequacy of existing regulatory mechanisms. In response to 

a very rapid decline in population numbers, in 1876, the State 

legislature amended a 1872 law that provided seasonal protection for 

elk, deer and pronghorn to include all bighorn sheep. Two years later, 

this law was amended, establishing a 4-year moratorium on the taking of 

any pronghorn, elk, mountain sheep or female deer. In 1882, this 

moratorium was extended indefinitely for bighorn sheep (Wehausen et al. 

1987; Wehausen et al. 1988). In 1971, California listed the California 

bighorn sheep as ``rare.'' The designation was changed to 

``threatened'' in 1984 to standardize the terminology of the amended 

California Endangered Species Act (Advisory Group 1997), and upgraded 

the species to ``endangered'' in 1999 (San Francisco Chronicle 1999). 

Pursuant to the California Fish and Game Code and the California 

Endangered Species Act, it is unlawful to import or export, take, 

possess, purchase, or sell any species or part or product of any 

species listed as endangered or threatened. Permits may be authorized 

for certain scientific, educational, or management purposes. The 

California Endangered Species Act requires that State agencies consult 

with the CDFG to ensure that actions carried out are not likely to 

jeopardize the continued existence of listed species.

    The California Fish and Game Code provides for management and 

maintenance of bighorn sheep. The policy of the State is to encourage 

the preservation, restoration, and management of California's bighorn 

sheep. The CDFG supports the concept of separating livestock from 

bighorn sheep, by creating buffers, to decrease the potential for 

disease transmission. Such separation would require the purchase and 

elimination of livestock allotments. However, the State does not have 

authority to regulate grazing practices on Federal lands. State listing 

has not prompted the BLM or USFS to effectively address disease 

transmission associated with Federal livestock grazing programs.

    Since the Sierra Nevada bighorn sheep was listed by the State of 

California in 1971, the CDFG has undertaken numerous efforts for the 

conservation of the sheep, including but not limited to--(1) intensive 

field studies; (2) reestablishment of three additional subpopulations 

in historical habitat; (3) creation, in 1981, of the Sierra Nevada 

Bighorn Sheep Interagency Advisory Group, including representatives 

from Federal, State, and local resource management agencies which has 

produced the Sierra Nevada Bighorn Sheep Recovery and Conservation Plan 

(1984) and a Conservation Strategy for Sierra Nevada Bighorn Sheep 

(1997); and (4) culling four mountain lions that were taking Sierra 

Nevada bighorn sheep, which played a significant role in the efforts to 

reestablish one subpopulation (Chow 1991, cited by Wehausen (1996)).

    Mountain lion hunting has not occurred in California since 1972 

(Torres et al. 1996). As a result of passage of Proposition 117 in 1990 

prohibiting the hunting or control of mountain lions, the CDFG does not 

have the authority to remove mountain lions to protect the Sierra 

Nevada bighorn sheep and secure their survival.

    Federal agencies have adequate authority to manage the land and 

activities under their administration to benefit the welfare of the 

bighorn sheep. Steps are being taken to enhance habitat through 

prescribed burning to improve forage and maintain open habitat, and to 

retire domestic sheep allotments that run adjacent to bighorn sheep 

habitat. For example, 650 acres were burned in 1997 in Lee Vining 

Canyon to reduce mountain lion hiding cover, and there

[[Page 19305]]

are plans to do more burns in other areas on USFS land (R. Perloff, 

pers. comm. 1999). However, in some cases, because of conflicting 

management concerns, conservation efforts are not proceeding as quickly 

as necessary. Although efforts have been underway for many years, the 

USFS has been unable to eliminate the known threat of contact between 

domestic sheep and the Sierra Nevada bighorn sheep by either 

eliminating adjacent grazing allotments, or modifying allotments such 

that a sufficient buffer zone exists that would prevent contact between 

wild and domestic sheep.

    In 1971, the State, in cooperation with the USFS, established a 

sanctuary for the Mount Baxter and Mount Williamson subpopulation of 

Sierra Nevada bighorn sheep and called it the California Bighorn Sheep 

Zoological Area (Zoological Area) (Wehausen 1979; Inyo National Forest 

Land Management Plan (LMP) 1988). About 16,564 hectares (41,000 acres) 

of USFS land was set aside for these two subpopulations. At the time, 

it was felt that the reason for the species' decline was related to 

human disturbance. The sanctuary was designed to regulate human use in 

some areas, and reduce domestic sheep/wild sheep interaction by 

constructing a fence below the winter range of the Mount Baxter 

subpopulation along the USFS boundary (Wehausen 1979). Adjacent summer 

range on NPS land was also given a restrictive designation to reduce 

human disturbance (Wehausen 1979). The Zoological Area continues to 

receive special management by the USFS; it encompasses land designated 

as wilderness and mountain sheep habitat (LMP 1988; R. Perloff, pers. 

comm. 1999).

    E. Other natural or manmade factors affecting its continued 

existence. The Sierra Nevada bighorn sheep population is critically 

small with a total of only about 100 sheep known from five 

subpopulations. There is no known interaction between the separate 

subpopulations. The Sierra Nevada bighorn sheep currently is highly 

vulnerable to extinction from threats associated with small population 

size and random environmental events.

    Although inbreeding depression has not been demonstrated in the 

Sierra Nevada bighorn sheep, the number of sheep occupying all areas is 

critically low. The minimum size at which an isolated group of this 

species can be expected to maintain itself without the deleterious 

effects of inbreeding is not known. Researchers have suggested that a 

minimum effective population size of 50 is necessary to avoid short-

term inbreeding depression, and 500 to maintain genetic variability for 

long-term adaptation (Franklin 1980). Small populations are extremely 

susceptible to demographic and genetic problems (Caughley and Gunn 

1996). Small populations suffer higher extinction probabilities from 

chance events such as skewed sex ratio of offspring, (e.g., fewer 

females being born than males). For example, the Mount Langley 

subpopulation has been declining. In 1996-97, out of a subpopulation of 

4 ewes and 10 rams, 5 lambs were born, of which 4 were female. Although 

a positive event for this subpopulation, it could have been devastating 

if the female:male ratio of offspring had been reversed (J. Wehausen, 

pers. comm. 1999).

    Small, isolated groups are also subject to extirpation by naturally 

occurring random environmental events, e.g., prolonged or particularly 

heavy winters and avalanches. In 1995, for example, a dozen sheep died 

in a single avalanche at Wheeler Ridge (J. Wehauser, pers. comm. 1999). 

Such threats are highly significant because currently the 

subpopulations are small and it is also common in bighorn sheep for all 

members of one sex to occur in a single group. During the very heavy 

winters in the late 1970s and early 1980s, there was no notable 

mortality in the subpopulations because they were using low elevation 

winter ranges (J. Wehausen, pers. comm. 1999).

    Competition for critical winter range resources can occur between 

bighorn sheep and elk and/or deer (Cowan and Geist 1971). However, 

competition between these species does not appear significant since 

deer and bighorn sheep readily mix on winter range, and the habitat 

overlap between elk and bighorn sheep is slight (Wehausen 1979).

    In addition to disease, mountain lion predation, and random natural 

events, other factors may contribute to bighorn sheep mortality. For 

example, two subpopulations (Wheeler Ridge and Lee Vining) have ranges 

adjacent to paved roadways exposing individuals from those 

subpopulations to potential hazards. Bighorn sheep have been killed by 

vehicles in Lee Vining Canyon on several occasions (V. Bleich, pers. 

comm. 1999).

Reason for Emergency Determination

    Under section 4(b)(7) of the Act and regulations at 50 CFR 424.20, 

we may emergency list a species if the threats to the species 

constitute an emergency posing a significant risk to its well-being. 

Such an emergency listing expires 240 days following publication in the 

Federal Register unless, during this 240-day period, we list the 

species following the normal listing procedures. We discuss the reasons 

why emergency listing the Sierra Nevada bighorn sheep as endangered is 

necessary below. In accordance with the Act, if at any time after we 

publish this emergency rule, we determine that substantial evidence 

does not exist to warrant such a rule, we will withdraw it.

    Historically, the Sierra Nevada bighorn sheep ranged throughout 

central and southern Sierra Nevada. The historical habitat of the 

Sierra Nevada bighorn sheep remains intact. However, the entire range 

of the species has been reduced to five subpopulations--the Mount 

Williamson and Mount Baxter subpopulations, which are composed of 

native sheep, and the Lee Vining Canyon, Wheeler Ridge, and Mount 

Langley subpopulations, which are descended from sheep taken from the 

Mount Baxter subpopulation and translocated to historical habitat. 

These subpopulations have decreased in numbers significantly in the 

last several years (see Table 1). As discussed under factors C, D, and 

E in the Summary of Factors Affecting the Species section above, the 

immediacy of threats to the Sierra Nevada bighorn sheep is so great to 

a significant proportion of the total population that the routine 

regular listing process is not sufficient to prevent losses that may 

result in extinction or loss of significant recovery potential. An 

emergency posing a significant risk to the well-being and continued 

survival of the Sierra Nevada bighorn sheep exists as the result of the 

continual exposure to predation (primarily mountain lion), and the 

effects of avoidance by bighorn sheep of areas in which they are 

particularly vulnerable to predation by mountain lions. The Sierra 

Nevada bighorn sheep is also threatened by the potential increase of 

contact with domestic sheep in the spring and summer and the 

transmission of disease. The factors creating an extreme situation are 

discussed in detail below.

    Because Sierra Nevada bighorn sheep exist only as a series of very 

small subpopulations vulnerable to extinction, the survival of Sierra 

Nevada bighorn sheep now depends on the most rapid possible increase in 

as many subpopulations as possible. These small subpopulations are 

vulnerable to extinction from chance demographic events and the 

continual loss of genetic variation if they remain small.

[[Page 19306]]

Vulnerability to Demographic Problems

    Five subpopulations remain that include a total of nine female 

demes (i.e., local populations) (Mount Langley--eight ewes, Mount 

Williamson--three ewes, Black Mountain--five ewes, Sand Mountain--five 

ewes, Sawmill Canyon--two ewes, Wheeler Ridge--17 ewes, Mount Gibbs--

two ewes, Tioga Crest--one ewe, Mount Warren--five ewes) (J. Wehausen, 

pers. comm. 1999). These demes are defined by separate geographic home 

range patterns of the females. Of these, the Mount Williamson, Black 

Mountain, and Tioga Crest demes appear not to use low elevation winter 

ranges at all, and they will probably go extinct as a result (J. 

Wehausen, pers. comm. 1999). The Black Mountain deme was previously 

part of the Sand Mountain deme (part of the Mount Baxter subpopulation) 

and became a separate deme after winter range abandonment occurred in 

the late 1980s. The five remaining ewes in this deme appear not to know 

of the Sand Mountain winter range, which lies considerably north of 

their home range. They were almost certainly all born after winter 

range abandonment on Sand Mountain. This deme has shown a steady 

decline in size (J. Wehausen, pers comm. 1999).

    There are six female demes that may persist, but all are still very 

vulnerable to extinction due to small size. Of the two ewes and lamb 

that spent February, 1998, at the mouth of Sawmill Canyon (another 

Mount Baxter subpopulation deme), only a ewe and a lamb remained when 

last seen there in 1998. Shortly after they were last seen, evidence of 

a mountain lion was found on the rocks where they had been weathering a 

month of severe winter storms. When the normal summer range of this 

deme of females was investigated twice last summer, it was difficult to 

find evidence of any sheep remaining. This deme may contain only a 

single remaining ewe, or none (J. Wehausen, pers. comm. 1999).

    The Sand Mountain deme has had only four ewes in it for almost this 

entire decade. During the summer of 1998, Dr. John Wehausen finally 

documented a yearling female with them, thus the total of five ewes 

listed above. However, the four adult ewes must now be approaching the 

ends of their lives, making this deme also very vulnerable to 

extinction, even if they have been showing some increased winter range 

use. Without successful births and recruitment of female lambs into 

this deme quickly, this deme will experience a decline.

    Currently, there is a large lion occupying the winter range areas 

used by members of the Mount Langley deme. These ewes have been using 

that winter range enough over the past three winters to be showing a 

subpopulation increase (recruitment of five lambs for four ewes in the 

past 2 years). This lion could easily reverse that trend by killing 

multiple members of this deme and discouraging them from using this 

winter range. These ewes can be expected to begin appearing on this 

winter range any day (J. Wehausen pers. comm. 1999).

    The Mount Warren deme that uses Lee Vining Canyon as a winter range 

continues to decline. Besides the loss of numerous ewes last winter or 

spring to unknown causes, one of two telemetered (radio-collared) ewes 

was lost to a lion on the winter range in April, 1998. The collar of 

the other ewe was recently dug out of a snow bank at 3050 m (10,000 ft) 

in Deer Creek, but biologists will be unable to investigate her cause 

of death until the summer of 1999 when the snow melts, allowing her 

carcass to be found. She was last documented alive in late October 

1998, but was not with a group of 13 sheep seen in mid-December, thus 

she may have died in November. This leaves only five ewes in this deme. 

If the lion that killed at least one ewe in April 1998 returns this 

spring, it might seriously compromise the future of this deme (J. 

Wehausen, pers. comm. 1999).

    With the likely extinction of some of the existing demes, the 

remaining demes become all the more important to the persistence of 

this distinct population segment. We do not know which demes may 

survive and which may die out. All population dynamics over the past 15 

years have been unanticipated (J. Wehausen, pers. comm. 1999). In 

short, it is not possible to predict population trajectories. 

Individual mountain lions can do enormous damage to any of these small 

demes, as can catastrophic events such as snow avalanches. The current 

larger size of the Wheeler Ridge deme does not preclude it from 

experiencing a sudden decline, as the Mount Warren deme experienced 

last winter (J. Wehausen, pers. comm. 1999).

    Every deme is critical to the survival of the DPS at this point. We 

do not know which ewes in each deme may prove to be the ones critical 

to persistence of those demes. Thus, every remaining female in every 

deme is critically important to the persistence of their demes.

    Lastly, the potential for contact with domestic sheep and the 

transmission of disease could, by itself, eliminate an entire deme. 

Domestic sheep continue to stray into Sierra Nevada bighorn sheep 

habitat. Recently, domestic sheep have come in close proximity to the 

resident bighorn sheep on numerous occasions, but, by good fortune, 

domestic sheep have not come into contact with bighorn sheep during 

these events.

    Vulnerability to demographic problems must be viewed as a 

combination of immediate threats of predation, changed habitat use due 

to the presence of mountain lions, the resultant decline in ewe 

nutrition and lamb survivorship, exposure to environmental 

catastrophes, and the transmission of disease from domestic sheep.

Vulnerability to Genetic Problems

    Also unknown is the current distribution of genetic variation among 

all of these subpopulations. It will be at least a year before fecal 

DNA research will shed some light on this question (J. Wehausen, pers 

comm. 1999). It is likely that each subpopulation has lost some genetic 

variability thereby reducing its ability for long-term adaptation. The 

ultimate goal of conserving this DPS must be to preserve as much of its 

genetic variation as possible. It is likely that all or some of the 

existing demes now contain some variation not represented in others. 

Once some measure of this distribution is known through DNA analysis, a 

possible goal will be to attempt to distribute that variation among as 

many subpopulations as possible. Until some measure of the distribution 

of genetic variation exists, every deme should be considered a 

significant portion of the overall population, just as they should from 

a demographic perspective. Maintenance of genetic variability requires 

preservation of rams in addition to ewes.

    In summary, it is now necessary to consider that every individual 

is currently a significant portion of the overall population of Sierra 

Nevada bighorn sheep because of the small number of sheep remaining and 

extreme vulnerability of every deme to extinction. Losses from 

predation and the potential for disease transmission through contact 

with domestic sheep are threats posing a significant risk to the well-

being of the DPS. For these

[[Page 19307]]

reasons, we find that the Sierra Nevada bighorn sheep is in imminent 

danger of extinction throughout all or a significant portion of its 

range and warrants immediate protection under the Act.

Critical Habitat

    Critical habitat is defined in section 3 of the Act as--(i) the 

specific area within the geographical area occupied by a species, at 

the time it is listed in accordance with the Act, on which are found 

those 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 

that such areas are essential for the conservation of the species. 

``Conservation'' means the use of all methods and procedures needed to 

bring the species to the point at which listing under the Act is no 

longer necessary.

    Section 4(a)(3) of the Act, and implementing regulations (50 CFR 

424.12) require that, to the maximum extent prudent and determinable, 

the Secretary designate critical habitat at the time the species is 

determined to be endangered or threatened. Our regulations (50 CFR 

424.12(a)) state that critical habitat is not determinable if 

information sufficient to perform required analysis of impacts of the 

designation is lacking or if the biological needs of the species are 

not sufficiently well known to permit identification of an area as 

critical habitat. Section 4(b)(2) of the Act requires us to consider 

economic and other relevant impacts of designating a particular area as 

critical habitat on the basis of the best scientific data available. 

The Secretary may exclude any area from critical habitat if he 

determines that the benefits of such exclusion outweigh the 

conservation benefits, unless to do such would result in the extinction 

of the species.

    We find that designation of critical habitat for the Sierra Nevada 

bighorn sheep is not determinable at this time. We have determined that 

information sufficient to perform required analysis of impacts of the 

designation is lacking. We specifically solicit this information in the 

proposed rule (see ``Public Comments Solicited'' section) published in 

this same issue of the Federal Register. When a ``not determinable'' 

finding is made, we must, within 2 years of the publication date of the 

original proposed rule, designate critical habitat, unless the 

designation is found to be not prudent. We will protect Sierra Nevada 

bighorn sheep habitat through section 7 consultations to determine 

whether Federal actions are likely to jeopardize the continued 

existence of the species, through the recovery process, through 

enforcement of take prohibitions under section 9 of the Act, and 

through the section 10 process for activities on non-Federal lands with 

no Federal nexus.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 

threatened under the Act include recognition, recovery actions, 

requirements for Federal protection, and prohibitions against certain 

activities. Recognition through listing encourages and results in 

conservation actions by Federal, State, and private agencies, groups 

and individuals. The Act provides for possible land acquisition and 

cooperation with the States and requires that recovery actions be 

carried out for all listed species. We discuss the protection required 

of Federal agencies and the prohibitions against taking and harm, in 

part, below.

    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) of the Act requires Federal agencies to 

confer informally with us on any action that is likely to jeopardize 

the continued existence of a proposed species or result in destruction 

or adverse modification of proposed critical habitat. If a species is 

subsequently listed, 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 such a species or to 

destroy or adversely modify its critical habitat. If a Federal agency 

action may affect a listed species or its critical habitat, the 

responsible Federal agency must enter into consultation with us. 

Federal agency actions that may require conference and/or consultation 

include those within the jurisdiction of the USFS, BLM, and NPS.

    We believe that protection of the Sierra Nevada bighorn sheep 

requires reduction of the threat of mountain lion predation, 

particularly during the months of April and May 1999 when bighorn sheep 

attempt to use low elevation winter ranges to obtain necessary 

nutrition after lambing, and ewes and lambs are most vulnerable to lion 

predation. Emergency listing will allow the Service to remove mountain 

lions that threaten Sierra Nevada bighorn sheep. Removal of mountain 

lions may not necessarily involve lethal techniques.

    We believe that protection of the Sierra Nevada bighorn sheep also 

requires reduction of the threat of disease transmission from domestic 

sheep by preventing domestic sheep from coming into contact with 

bighorn sheep. We will work with the USFS to reduce the threat of 

disease transmission by domestic sheep. Reduction of this threat may 

involve elimination of grazing allotments adjacent to bighorn sheep 

habitat, or modifying allotments to create a sufficient buffer zone 

that would prevent contact between domestic sheep and bighorn sheep.

    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. The prohibitions, as codified at 50 CFR 17.21, 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 our agents and State 

conservation agencies.

    Permits may be issued to carry out otherwise prohibited activities 

involving endangered wildlife species under certain circumstances. 

Regulations governing permits are at 50 CFR 17.22 and 17.23. For 

endangered species, such permits are available for scientific purposes, 

to enhance the propagation or survival of the species, or for 

incidental take in connection with otherwise lawful activities.

[[Page 19308]]

    It is our policy, 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 a listing on proposed and 

ongoing activities within a species' range. Activities that we believe 

could potentially result in take include, but are not limited to:

    (1) Unauthorized trapping, capturing, handling or collecting of 

Sierra Nevada bighorn sheep. Research activities involving trapping or 

capturing Sierra Nevada bighorn sheep will require a permit under 

section 10(a)(1)(A) of the Act.

    (2) Unauthorized livestock grazing that results in transmission of 

disease or habitat destruction by the accidental or intentional escape 

of livestock.

    Activities that we believe are unlikely to result in a violation of 

section 9 are:

    (1) Possession, delivery, or movement, including interstate 

transport and import into or export from the United States, involving 

no commercial activity, of dead specimens of Sierra Nevada bighorn 

sheep that were collected prior to the date of publication of this 

emergency listing rule in the Federal Register;

    (2) Unintentional vehicle collisions resulting in death or injury 

to Sierra Nevada bighorn sheep, when complying with applicable laws and 

regulations; and

    (3) Normal, authorized recreational activities in designated 

campsites or recreational use areas and on authorized trails.

    Questions regarding any specific activities should be directed to 

our Ventura Fish and Wildlife Office (see ADDRESSES section). Requests 

for copies of the regulations regarding listed wildlife and about 

prohibitions and permits may be addressed to the U.S. Fish and Wildlife 

Service, Ecological Services, Endangered Species Permits, 911 Northeast 

11th Avenue, Portland, Oregon 97232-4181 (telephone 503/231-2063; 

facsimile 503/231-6243).

National Environmental Policy Act

    We have determined that Environmental Assessments and Environmental 

Impact Statements, as defined in 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. We published a notice outlining our reasons for this 

determination in the Federal Register on October 25, 1983 (48 FR 


Paperwork Reduction Act

    This rule does not contain any new collections of information other 

than those already approved under the Paperwork Reduction Act, 44 

U.S.C. 3501 et seq., and assigned Office of Management and Budget 

clearance number 1018-0094. 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 control number. For additional 

information concerning permit and associated requirements for 

endangered species, see 50 CFR 17.21 and 17.22.

References Cited

    A complete list of references cited in this rule is available upon 

request from the Ventura Fish and Wildlife Office of the U.S. Fish and 

Wildlife Service (see ADDRESSES section).


    The primary author of this emergency rule is Carl Benz of the 

Ventura Fish and Wildlife Office of the U.S. Fish and Wildlife Service 

(see ADDRESSES section).

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 

recordkeeping requirements, Transportation.

Regulation Promulgation

    Accordingly, part 17, subchapter B of chapter I, title 50 of the 

Code of Federal Regulations, is amended 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. In Sec. 17.11(h) add the following to the List of Endangered and 

Threatened Wildlife in alphabetical order under MAMMALS:

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



                   *                  *                  *                  *                  *                  *                  *

Sheep, Sierra Nevada bighorn.....  Obis canadensis       U.S.A. (western      U.S.A. (CA-Sierra    E                       660           NA           NA

                                    californiana.         conterminous         Nevada).

                                                          states), Canada


                                                          Mexico (north).

                   *                  *                  *                  *                  *                  *                  *


[[Page 19309]]

    Dated: April 14, 1999.

Jamie Rappaport Clark,

Director, Fish and Wildlife Service.

[FR Doc. 99-9935 Filed 4-19-99; 8:45 am]