[Federal Register: June 6, 2007 (Volume 72, Number 108)]
[Proposed Rules]               
[Page 31264-31268]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]



Fish and Wildlife Service

50 CFR Part 17

Endangered and Threatened Wildlife and Plants; 90-Day Finding on 
a Petition To Remove the Utah (Desert) Valvata Snail (Valvata 
utahensis) from the List of Endangered and Threatened Wildlife

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 90-day petition finding and initiation of status 


SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
90-day finding on a petition to remove the Utah (desert) valvata snail 
(Valvata utahensis) from the Federal List of Endangered and Threatened 
Wildlife (List) pursuant to the Endangered Species Act (Act). We find 
that the petition presents substantial scientific information that 
delisting the Utah valvata snail may be warranted, and are initiating a 
status review. We plan to conduct this review concurrent with the 
ongoing status review initiated on April 11, 2006 (71 FR 18345), which 
we are required to make every 5 years under section 4(c)(2)(A) of the 
Act. We are requesting submission of any new information on the Utah 
valvata snail since its original listing as an endangered species in 
1992. At the conclusion of these simultaneous reviews, we will make the 
requisite recommendation under section 4(c)(2)(B) of the Act and will 
issue a 12-month finding on the petition, as provided in section 
4(b)(3)(B) of the Act.

DATES: The finding announced in this document was made on June 6, 2007. 
To be considered in the 12-month finding on this petition or the 5-year 
review, comments and information must be submitted to us by September 
4, 2007.

ADDRESSES: You may submit new information, materials, comments, or 
questions concerning this species by any one of the following methods:
    1. You may submit comments and information to the Field Supervisor, 
Attention: Utah Valvata Snail Comments, Snake River Fish and Wildlife 
Office, 1387 S. Vinnell Way, Suite 368, Boise, ID 83709.
    2. You may hand-deliver written comments and information to the 
above address.
    3. You may fax your comments to 208-378-5262.
    4. You may go to the Federal rulemaking Internet portal: http://www.regulations.gov.
 Follow the instructions for submitting comments.    5. You may e-mail your comments to fw1srbocomment@fws.gov..

    Please include ``Utah Valvata Snail Comments'' in the subject line 
for faxes and e-mails. Please submit electronic comments in unformatted 
text, and avoid the use of special characters and encryption.

FOR FURTHER INFORMATION CONTACT: Susan Burch, Fish and Wildlife 
Biologist, Snake River Fish and Wildlife Office (see ADDRESSES); 
telephone: 208-378-5243; or e-mail: susan_burch@fws.gov.


Public Information Solicited

    When we make a finding that substantial information exists to 
indicate that listing or delisting a species may be warranted, we are 
required to promptly commence a review of the status of the species. To 
ensure that the status review is complete and based on the best 
available scientific and commercial information, we are soliciting any 
additional information, comments, or suggestions on the Utah valvata 
snail from the public, State and Federal agencies, Tribes, the 
scientific community, industry or environmental entities, or any other 
interested parties. Information sought includes any data regarding 
historical and current distribution, biology and ecology, ongoing 
conservation measures for the species or its habitat, and threats to 
the species or its habitat. We also request information regarding the 
adequacy of existing regulatory mechanisms.
    Please note that comments merely stating support or opposition to 
the actions under consideration without providing supporting 
information, although noted, will not be considered in making a 
determination, as section 4(b)(1)(A) of the Act directs that 
determinations as to whether any species is a threatened or endangered 
species shall be made ``solely on the basis of the best scientific and 
commercial data available.'' At the conclusion of the status review, we 
will issue the 12-month finding on the petition, as provided in section 
4(b)(3)(B) of the Act (16 U.S.C. 1531 et seq.).
    If you wish to comment or provide information, you may submit your 
comments and materials concerning this finding to the Field Supervisor 
(see ADDRESSES) by the date listed in the DATES section.
    Before including your address, phone number, e-mail address, or 
other personal identifying information in your comment, you should be 
aware that your entire comment--including your personal identifying 
information--may be made publicly available at any time. While you can 
ask us in your comment to withhold your personal identifying 
information from public review, we cannot guarantee that we will be 
able to do so. If you wish us to withhold your name and/or address, you 
must state this prominently at the beginning of your comment. However, 
we will not consider anonymous comments. Comments and materials 
received will be available for public inspection, by appointment, 
during normal business hours at the address listed in the ADDRESSES 


    Section 4(b)(3)(A) of the Endangered Species Act (Act) of 1973, as 
amended (16 U.S.C. 1531 et seq.), requires that we make a finding on 
whether a petition to list, delist, or reclassify a species presents 
substantial scientific or commercial information indicating that the 
petitioned action may be warranted.

[[Page 31265]]

The finding is based on information contained in the petition and 
information otherwise available in our files at the time we make the 
finding. To the maximum extent practicable, we are to make the finding 
within 90 days of receiving the petition, and publish our notice of the 
finding in the Federal Register.
    This finding summarizes the information included in the petition 
and information available to us at the time of the petition review. 
Under section 4(b)(3)(A) of the Act and our regulations in 50 CFR 
424.14(b), our review of a 90-day finding is limited to a determination 
of whether the information in the petition meets the ``substantial 
scientific or commercial information'' threshold. Our standard for 
substantial information with regard to a 90-day petition finding is 
``that amount of information that would lead a reasonable person to 
believe that the measure proposed in the petition may be warranted'' 
(50 CFR 424.14(b)). If we find that substantial information was 
presented, we are required to promptly commence a review of the status 
of the species and publish the results of that status review in a 12-
month finding.

Species Information

    The Utah valvata snail is a habitat generalist, occupying coldwater 
springs, spring creeks, the mainstem Snake River, and reservoirs in 
both fine sediments and more coarse substrates at a variety of water 
depths (Hinson 2006, pp. 30-33). Utah valvata snails have been 
documented in discontinuous colonies along a 260-mile stretch of the 
Snake River in southern and eastern Idaho from Upper Salmon Falls Dam 
in southern Idaho (River Mile (RM) 581.3) upstream to the State Highway 
33 Bridge on the Henry's Fork in eastern Idaho (Hinson 2006, p. 15). 
Colonies are also known to exist in Snake River tributaries (e.g., the 
Big Wood River and Box Canyon Creek) and in coldwater springs adjacent 
to the Snake River (e.g., Thousand Springs Preserve) (reviewed by 
Hinson 2006, p. 15).
    The Utah valvata snail is univoltine, meaning it has a 1-year life 
cycle. Emergence of new cohorts of the Utah valvata snails occurs 
throughout the year, depending on habitat (Frest and Johannes 1992, p. 
15; U.S. Bureau of Reclamation (USBR) 2002, pp. 6-7; USBR 2003, pp. 9-
12; Lysne 2003, p. 93), and is followed by rapid growth through the 
summer and fall. Over winter, snails become dormant (Cleland 1954, p. 
170; Lysne 2003, p. 83, USBR 2003, pp. 9-12). Following the cessation 
of dormancy in spring, growth continues through summer until sexual 
maturity is reached at 4 to 5 millimeters (mm) of length (Hershey 1990, 
p. 29; Lysne and Koetsier 2006, p. 287). Reproduction and spawning 
occur asynchronously between March and October, depending on habitat, 
with the majority of young spawned between August and October (Cleland 
1954, p. 172; USBR 2003, p. 9). Emergence of a new cohort follows 
approximately two weeks after oviposition (Cleland 1954, p. 170; Heard 
1963, p. 66; Dillon 2000, p. 103) and senescent snails (i.e., those 
approximately 1 year old) die shortly after reproduction (Cleland 1954, 
pp. 170-171; Lysne and Koetsier 2006, p. 287).
    We listed the Utah valvata snail as endangered on December 14, 1992 
(57 FR 59244). At that time, we determined that the Utah valvata snail 
was threatened by construction of new hydropower dams, the operation of 
existing hydropower dams, degraded water quality, water diversions, the 
introduced New Zealand mudsnail (Potamopyrgus antipodarum), and the 
lack of existing regulatory protections (57 FR 59244). The Utah valvata 
snail was described as existing ``at a few springs and mainstem Snake 
River sites in the Hagerman Valley and at a few sites below American 
Falls Dam downstream to Burley [Idaho].'' We published the Snake River 
Aquatic Species Recovery Plan, which included the Utah valvata snail, 
in 1995 (Service 1995). Critical habitat has not been designated for 
this species.

Review of Petition

    On December 26, 2006, we received a petition from the Governor of 
Idaho and attorneys for several irrigation districts and canal 
companies requesting that the Utah valvata snail be removed from the 
List. The delisting petition cites a recent status review conducted by 
Steward & Associates (Hinson 2006), a review of Utah valvata snail 
sampling methodology (D.R. Hinson and C. Steward (Steward & 
Associates), in litt. 2007), a memorandum addressing perceived threats 
to Utah valvata snail from 1996 to 2006 (Barker Rosholt & Simpson LLP, 
in litt. 2006), the Mid-Snake Springs Habitat Protection Plan (Wilkison 
2005), species data from the Thousand Springs Preserve (Idaho Power 
2006, unpublished data), water quality data from Idaho Department of 
Environmental Quality (IDEQ 2007), and U.S. Bureau of Reclamation data 
for the Utah valvata snail (USBR 2002, 2003, 2005). The petition 
clearly identified itself as a petition and included the requisite 
identification information for the petitioners, as required in 50 CFR 
424.14(a). The petition cited information on the natural history of the 
Utah valvata snail, its population status, and advances in knowledge 
about the species' ecology and threats since listing. The petition 
states that many of the threats identified in the 1992 listing rule no 
longer exist or have been attenuated by subsequent actions. It also 
states that the Utah valvata snail is more abundant, is more 
continuously distributed, and exists in more diverse habitats than 
previously recorded.

Threats Analysis

    The factors for listing, delisting, or reclassifying a species are 
described at 50 CFR 424.11. We may delist a species only if the best 
scientific and commercial data available substantiate that it is 
neither endangered nor threatened. Delisting may be warranted as a 
result of: (1) Extinction, (2) recovery, and/or (3) a determination 
that the original data used for classification of the species as 
endangered or threatened were in error.
    Section 4(a)(1) of the Act requires that we determine whether a 
species is endangered or threatened based on one or more of the five 
following factors: (A) Present or threatened destruction, modification, 
or curtailment of habitat or range; (B) overutilization for commercial, 
recreational, scientific, or educational purposes; (C) disease or 
predation; (D) inadequacy of existing regulatory mechanisms; or (E) 
other natural or manmade factors affecting its continued existence. In 
making this 90-day finding, we evaluated whether information presented 
in the December 2006 petition, when considered along with information 
in our files, constitutes substantial scientific or commercial 
information such that delisting may be warranted. Our evaluation of 
this information is presented below.

A. Present or Threatened Destruction, Modification, or Curtailment of 
the Species' Habitat or Range

Habitat Use
    The petitioners claim that Utah valvata snails are able to live in 
a variety of habitats previously thought to be unsuitable for the 
species, including reservoirs. They provided a status report by Hinson 
(2006) as the primary source of information to support this claim. 
Hinson (2006, p. 21) used available data from the Bureau of 
Reclamation, Idaho Power Company, Hinson & Falter, the Idaho Department 
of Fish and Game, the Service, and the Idaho Transportation Department 
to analyze the current distribution of Utah valvata snails related to 
habitat features (i.e., depth

[[Page 31266]]

and dominant substrate size). Based on this analysis, Hinson (2006, pp. 
3, 23-32) reported Utah valvata snails using a number of substrates 
(fines, cobbles, gravel), habitat types (river, springs, reservoirs), 
depths (from less than 1.6 feet (ft) (0.5 meter (m)) to greater than 
32.8 ft (10 m)), and water temperatures (from 40.1 degrees Fahrenheit 
([deg]F) (4.5 degrees Celsius ([deg]C)) to 66.6 [deg]F (19.2 [deg]C)). 
The snails have also been found in areas of low and high concentrations 
of aquatic plants, and, in one case, were found in very fine, black, 
organically enriched sediments with dense submerged aquatic plant 
communities and attached filamentous (long thread-like) algae (Hinson 
2006, pp. 30-33).
    At the time of listing, we stated: ``In the Snake River, V. 
utahensis lives in deep pools adjacent to rapids or in perennial 
flowing waters associated with large spring complexes. The species 
avoids areas with heavy currents or rapids. The snail prefers well-
oxygenated areas of non-reducing calcareous mud or mud-sand substrate 
among beds of submergent aquatic vegetation. The species is absent from 
pure gravel-boulder bottoms'' (57 FR 59244, p. 59245).
    We accept the petitioners' characterization of Utah valvata snail 
habitat use and find that they have presented substantial information 
suggesting that current information about Utah valvata snail habitat 
use may be different than indicated by the best available information 
at the time of listing in 1992.
    Based primarily on a status report by Hinson (2006), the 
petitioners claim that the species is more widely distributed than 
recorded at the time of listing in 1992. Hinson (2006, p. 15) reported 
that Utah valvata snails occupy discontinuous colonies in a 260-mile 
(418-kilometer) range in the Snake River Basin from Upper Salmon Falls 
Dam (RM 581.3) upstream to the State Highway 33 bridge on the Henry's 
Fork. Colonies are also known to exist in habitats adjacent to mainstem 
Snake River habitats, including the Big Wood River (joins the Snake 
River at RM 571), Box Canyon Creek (joins the Snake River at RM 588), 
and Thousand Springs Preserve (joins the Snake River at RM 585) 
(reviewed by Hinson 2006, p. 15). Based on a collection of empty shells 
of recent origin, colonies may also exist in Magic Reservoir, upstream 
of the Big Wood River colony (J. Keebaugh, Orma J. Smith Museum of 
Natural History, pers. comm. 2006, cited in Hinson 2006, p. 15). At 
present, the most abundant colonies of Utah valvata snails known to 
exist in the Snake River Basin occur in river and reservoir habitats 
from Minidoka Dam (RM 675) upstream to the middle portion of American 
Falls Reservoir (approximately RM 725) (reviewed by Hinson 2006, p. 
    At the time of listing, we stated: ``The Utah valvata snail 
historically occurred from river mile 492 (near Grandview) to river 
mile 585 just above Thousand Springs with a disjunct population in the 
American Falls Dam tailwater near Eagle Rock damsite at river mile 709. 
The taxa was known historically from northern Utah, although recent 
mollusk surveys throughout the State revealed no live sites and the 
species is believed extirpated there (Clarke 1991). At present, this 
species occurs in a few springs and mainstem Snake River sites in the 
Hagerman Valley and a few sites below American Falls Dam downstream to 
Burley (Beak 1987; Taylor 1987)'' (57 FR 59245).
    We accept the petitioners' characterization of the Utah valvata 
snail's current range and find that they have presented substantial 
information indicating that the current range of the Utah valvata snail 
may be significantly larger than the range we described in our 1992 
listing rule.
Construction of New Hydropower Dams
    The petition states that threats to Utah valvata snail habitat from 
future hydro-power development are not as they were perceived when the 
species was listed in 1992. The petitioners provided a document from 
the State of Idaho (Idaho 2006), indicating that all recent permits for 
the construction of new dams along the Mid-Snake River have either 
lapsed or have been denied by the Federal Energy Regulatory Commission 
(FERC). They also provided the following documents as evidence that 
specific permits are no longer moving forward: (1) A 2002 notice of 
surrender of preliminary permit for the River Side Project (FERC 
2002a), (2) 2002 orders denying application for preliminary permits for 
the Eagle Rock (FERC 2002b) and Star Falls Hydroelectric Projects (FERC 
2002c), and (3) a 2003 notice of surrender of preliminary permit for 
the Auger Falls Project (FERC 2003).
    At the time of listing, there were six active proposals for new 
hydroelectric projects in the middle-Snake River. In our listing rule, 
we stated: ``Six proposed hydroelectric projects, including two high 
dam facilities, would alter free flowing river reaches within the 
existing range of [the Utah valvata snail]. Dam construction threatens 
the [Utah valvata snail] through direct habitat modification and 
moderates the Snake River's ability to assimilate point and non-point 
pollution. Further hydroelectric development along the Snake River 
would inundate existing mollusk habitats through impoundment, reduce 
critical shallow, littoral shoreline habitats in tailwater areas due to 
operating water fluctuations, elevate water temperatures, reduce 
dissolved oxygen levels in impounded sediments, and further fragment 
remaining mainstem populations or colonies of these snails'' (57 FR 
    We have no information in our files suggesting that future 
hydropower development in the middle-Snake River is likely to occur and 
we therefore accept the petitioners' claim that the threats from 
hydropower development may have dissipated since the time of listing.
Water Quality
    A threats analysis provided by the petitioners states that threats 
to Utah valvata snail habitat from water pollution are not as they were 
perceived when the species was listed in 1992 (Barker et al. 2006, in 
litt., p. 10). The petitioners presented data on improvements to Snake 
River water quality and on changes in our understanding of Utah valvata 
snail's tolerance of nutrient-rich (e.g., nitrogen and phosphorus) 
water in the Snake River resulting from return flows from irrigated 
agriculture, runoff from feedlots and dairies, hatchery effluent, 
municipal sewage effluent, and other point and non-point discharges. 
The Utah valvata snail status report provided by the petitioners 
(Hinson 2006, p. 19) noted that the U.S. Bureau of Reclamation (2003) 
conducted studies measuring the organic content in the sediment (ash-
free dry weight) where Utah valvata snails are found in an attempt to 
create an index that relates snail densities with available forage. The 
highest Utah valvata snail densities sampled coincided with lower Lake 
Walcott reservoir habitat that had the greatest percentage of organic 
content in the sediments, suggesting that Utah valvata snails can reach 
their greatest densities in areas that are subject to high 
concentrations of nitrogen and phosphorus (Hinson 2006, p. 19).
    At the time of listing, we stated: ``The quality of water in 
[snail] habitats has a direct effect on the species survival. The [Utah 
valvata snail] require[s] cold, well-oxygenated unpolluted water for 
survival. Any factor that leads to a deterioration in water quality 
would likely extirpate [the Utah valvata snail]'' (57 FR 59244, p. 
    Therefore, we find that the petitioners have presented substantial 

[[Page 31267]]

indicating that Utah valvata snails may be more tolerant of nutrient-
rich waters than indicated by the best available information at the 
time of listing in 1992.

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

    The petitioners did not provide information regarding the 
overutilization of Utah valvata snails for commercial, recreational, 
scientific, or educational purposes. We did not consider this factor 
applicable to our listing decision in 1992, and we do not have 
information in our files suggesting that overutilization is a threat to 
the species.

C. Disease or Predation

    The petitioners did not provide information regarding the effects 
of disease or predation on Utah valvata snails. At the time of listing 
we stated that changes in the fish fauna of the middle Snake River had 
been suggested as a potential threat to the Utah valvata snail (57 FR 
59244, p. 59253). At that time there was no data to support this 
suggestion, and we did not consider this factor to be significant in 
our listing decision. Currently, we have no information in our files 
suggesting that disease or predation are significant threats to the 
Utah valvata snail.

D. The Inadequacy of Existing Regulatory Mechanisms

    The petitioners provided numerous documents regarding surface water 
quality programs, water rights, aquifer recharge, and groundwater 
management in the Snake River and Snake River Plain aquifer (e.g., 
Idaho 2004; Idaho 2005; IDWR 2006). These documents indicate that the 
State of Idaho has regulatory mechanisms to limit or exclude the 
development of new surface water or groundwater rights within the range 
of the Utah valvata snail. These documents also indicate that the State 
has regulatory mechanisms to prioritize existing water rights based on 
    At the time of listing, we found inadequate regulatory mechanisms 
to be a threat because (1) regulations were inadequate to curb further 
water withdrawal from groundwater spring outflows or tributary spring 
streams, (2) it was unlikely that pollution control regulations would 
reverse the trend in nutrient loading in the near future, (3) there was 
a lack of protections for invertebrate species in Idaho, and (4) 
regulations did not require FERC or the U.S. Army Corp of Engineers to 
address Service concerns regarding licensing hydroelectric projects or 
permitting projects under the Clean Water Act for unlisted snails.
    Information provided by the petitioner, along with information in 
our files, suggests that the threat to Utah valvata snails from 
inadequate regulatory mechanisms may be less than indicated by the best 
available information at the time of listing. There are now regulatory 
mechanisms to limit future surface water and groundwater development, 
and some pollution control regulations have been implemented.

E. Other Natural or Manmade Factors Affecting Its Continued Existence

    The status report provided by the petitioner (Hinson 2006) states 
that threats to the Utah valvata snail from the New Zealand mudsnail 
(Potamopyrgus antipodarum) are not as they were perceived when the 
species was listed in 1992. According to Hinson (2006, pp. 41-42), the 
fact that Utah valvata snails and New Zealand mudsnails frequently 
occur in the same samples indicates that these two species are able to 
co-exist, which either indicates that resources are not limiting or 
that the snails actually have slightly different algae preferences.
    However, Hinson (2006, p. 41) also notes that the overlap in 
habitat utilization between the Utah valvata snail and the New Zealand 
mudsnail could lead to direct competition for resources between these 
two species. Hinson (2006, p. 41) states: ``P. antipodarum densities 
have been steadily increasing in reservoir habitats of the Snake River 
(e.g., Lake Walcott) (USBOR 2003; USBOR 2004a). This overlap in habitat 
utilization between V. utahensis and P. antipodarum could lead to 
direct competition for resources between these two species. Known 
densities of the exotic P. antipodarum in the Middle Snake River can 
exceed 800,000 individuals per square meter (Minshall 1993). This 
factor alone increases the likelihood that V. utahensis can be 
outcompeted by P. antipodarum and physically displaced in areas where 
the two species overlap. P. antipodarum populations in the Snake River 
Basin have been shown to reproduce rapidly and quickly deplete growths 
of periphytic algae (USFWS 2005), which is known to be an important 
food source for V. utahensis and many of the other listed Snake River 
    At the time of listing, we stated that New Zealand mudsnails were 
not abundant in coldwater springflows with colonies of the Utah valvata 
snail, but that they did compete with the Utah valvata snail in the 
mainstem Snake River (57 FR 59244, p. 59254). We have no direct 
evidence that New Zealand mudsnails have displaced colonies of Utah 
valvata snails, but New Zealand mudsnails have been documented in dense 
mats (at densities of nearly 400 individuals per square inch) in free-
flowing habitats within the range of the Utah valvata snail (57 FR 
59244, p. 59254). Furthermore, New Zealand mudsnails have become 
established in every spring-fed creek or tributary to the Snake River 
in the Hagerman Reach that has been surveyed.
    Based on information provided by the petitioner, along with 
information in our files, New Zealand mudsnails likely compete with 
Utah valvata snails for food or space. Although the information 
provided by the petitioners indicates that the Utah valvata snail and 
New Zealand mudsnail co-occur in various locations, the petitioners 
acknowledge that, given the densities that New Zealand mudsnails can 
achieve, there is an increased likelihood that ``V. utahensis can be 
outcompeted by P. antipodarum and physically displaced in areas where 
the two species overlap.'' Therefore, we find that Hinson's (2006) 
analysis is largely consistent with our analysis at the time of listing 
in 1992, and that New Zealand mudsnails may still be a substantive 
threat to the Utah valvata snail.


    We have reviewed the delisting petition and the supporting 
documents, as well as other information in our files. We find that the 
delisting petition and other information in our files presents 
substantial information indicating that delisting the Utah valvata 
snail may be warranted, and we are initiating a status review. 
Petitioners have provided a detailed status report that updates the 
state of knowledge regarding Utah valvata snail habitat use, 
distribution, and threats. The status report provides substantial 
information indicating that the Utah valvata snail may be more widely 
distributed than previously recorded and that it can occur in a wide 
variety of habitat types, substrates, depths, and water temperatures. 
Information provided by the petitioners also indicates that threats 
from hydropower development are not what we perceived when we listed 
the species in 1992, and that additional regulatory mechanisms now 
exist that could limit water development and improve water quality in 
Utah valvata snail habitat. New Zealand mudsnails appear to be a 
persistent threat to the Utah valvata snail, but the significance of 
this threat must be more fully evaluated in the context of the

[[Page 31268]]

remaining threats and the species' overall status.

5-Year Review

    Section 4(c)(2)(A) of the Act requires that we conduct a status 
review of listed species at least once every 5 years. We are then, 
under section 4(c)(2)(B), to determine whether any species should be 
removed from the List (delisted), or reclassified from endangered to 
threatened, or threatened to endangered. We initiated a 5-year review 
for the Utah valvata snail on April 11, 2006 (71 FR 18345). We are 
currently in the process of completing our 5-year review and will 
incorporate that review into our 12-month finding.


    A complete list of all references cited in this finding is 
available, upon request, from the Snake River Fish and Wildlife Office 
(see ADDRESSES section).


    The primary author of this document is Jesse D'Elia, Pacific 
Regional Office, Portland, Oregon.


    The authority for this action is section 4 of the Endangered 
Species Act of 1973 (16 U.S.C. 1531 et seq.).

    Dated: May 25, 2007.
Randall B. Luthi,
Acting Director, Fish and Wildlife Service.
 [FR Doc. E7-10885 Filed 6-5-07; 8:45 am]