[Federal Register Volume 64, Number 75 (Tuesday, April 20, 1999)]
[Rules and Regulations]
[Pages 19300-19309]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-9935]


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DEPARTMENT OF THE INTERIOR

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.

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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).

Background

    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. 
1987).
    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 
1980).

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 
California.

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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)
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                                                    Number of     Total
                       Year                        populations    sheep
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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 
action.

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 
follows:
    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

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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 
1979).
    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 
time.
    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 
1982).
    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 
1950).
    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 
49244).

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).

Author

    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:

PART 17--[AMENDED]

    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
--------------------------------------------------------------------------------------------------------------------------------------------------------
MAMMALS
 
                   *                  *                  *                  *                  *                  *                  *
Sheep, Sierra Nevada bighorn.....  Obis canadensis       U.S.A. (western      U.S.A. (CA-Sierra    E                       660           NA           NA
                                    californiana.         conterminous         Nevada).
                                                          states), Canada
                                                          (southwest),
                                                          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]
BILLING CODE 4310-55-P