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Physical Resources:  Air Quality / Night Sky / Noise / Water / Paleontology / Geology

Biological Resources:  Vegetation and Wildlife / Species of Special Consideration / Species Restoration

Physical Resources

Air Quality and Visibility

The management and enforcement of the Clean Air Act’s air quality standards in the Death Valley National Park area is conducted by two entities, the Mojave Desert Air Quality Management District (MDAQMD) and the Great Basin Unified Air Pollution Control District (GBUAPCD). The Mojave Desert Air Quality Management District includes the desert portion of San Bernardino County (within the South East Desert Air Basin) and the Great Basin Unified Air Pollution Control District includes Inyo and Mono Counties (within the Great Basin Valley Air Basin).

The Congress established the Prevention of Significant Deterioration program as part of the Clean Air Act. To facilitate the implementation of this program, an area classification scheme was established. This classification scheme has class I receiving the highest degree of protection with only small amounts of certain kinds of additional air pollution (sulfur dioxide and particulate matter) allowed. The other two areas are class II, which allows moderate increases in certain air pollutants; and class III, which allows a large amount of new air pollution (Congress has yet to designate any class III areas). There are no class I areas in the California Mojave Desert. Death Valley National Park is a class II "floor" area, meaning that it may never be redesignated to class III.

Federal and State Nonattainment Areas

The Clean Air Act developed national ambient air quality standards for a finite number of pollutants called "criteria pollutants." The criteria pollutants are: sulfur dioxide, carbon monoxide, total suspended particulates, nitrogen oxides, lead, ozone, and particulate matter less than 10 microns in diameter (PM₁₀). State of California standards, which are stricter than federal standards, include additional standards for hydrogen sulfide and particulate sulfates.

Nonattainment areas are areas that are not in compliance with the National Ambient Air Quality Standards, and therefore must reduce pollution to reach compliance. Nonattainment requirements include reasonable controls on existing stationary sources, most stringent controls on new sources, emission offsets, transportation control plans (including inspection and maintenance), and sanctions for failing to submit a plan.

The Environmental Protection Agency has classified most of the South East Desert Air Basin as nonattainment areas for ozone. Mono County levels have exceeded the National Ambient Air Quality Standards and may be designated nonattainment for ozone in the future. The Searles Valley planning area is also nonattainment for state hydrogen sulfide and particulate sulfate standards (Searles Valley planning area shares its boundaries with three air pollution control districts: the Mojave Desert, Great Basin Unified, and Kern County). The San Bernardino County portion of Death Valley National Park is in nonattainment for California’s state ozone standards.

Federal PM₁₀ nonattainment areas include the San Bernardino County desert area, Owens Valley, Mammoth Lakes, Mono Basin, and the Searles Valley planning area. Mono and the eastern portion of Inyo counties have not recorded PM₁₀ emissions in excess of the national standards.

Pollution Sources

Visibility is probably the most important air quality resource within the desert region and is the most easily affected by activities that generate dust (especially fine particulates) and sulfur dioxide. Visibility impacts occur from long-range transport of pollutants from as far away as the San Joaquin Valley and the Los Angeles basin (RESOLVE study 1988, cited in BLM 1995a). The RESOLVE study estimates that two-thirds of the visibility degradation was attributed to sources within the San Joaquin Valley with the balance coming from local sources and the Los Angeles basin (BLM 1995a).

One nearby source of pollution is the Searles Valley (Trona) complex that produces soda ash, borax, potash, and other chemicals from Searles Dry Lake. Other nearby sources of emissions include Owens Lake, Owens Lake Soda Ash Company, U.S. Army’s National Training Center at Fort Irwin, China Lake Naval Air Weapons Station, Briggs Mine, and Panamint Valley Limestone Quarry. Air quality monitoring activities occur at Death Valley National Park and at the Briggs Mine. The Briggs Mine transmits (via the Internet) its air quality data daily to the Great Basin Unified Air Pollution Control District.

Exposed lakebeds and farmlands lie in the Owens Valley and Mono Basin between mountain ranges. Wind-carried dust from these exposed lands in the valley affect air quality over the area (Inyo NFS 1988). Visibility has been affected to the extent that Department of Defense test flights over the Owens Valley are hampered or shut down 6 to 12 times each year (Inyo NFS 1988). The county, the Great Basin Unified Air Pollution Control District, the city of Los Angeles, the Department of Defense, and the Inyo National Forest are making coordinated efforts to resolve this concern.

Local pollution sources in the desert consist primarily of particulate matter from off-road vehicles, windblown soil, mining operations, livestock grazing, and agricultural activities. These sources have left certain areas denuded or sparsely vegetated, allowing wind erosion to occur and air quality to suffer, occasionally causing particulate standards violations at some locations.

Night Sky

Within Death Valley National Park, the night sky toward the southeast is noticeably impacted by lights from Las Vegas, perhaps with some Pahrump influence. This is especially apparent while heading south from Grapevine and Stovepipe toward Cow Creek and Furnace Creek. Other light sources are essentially limited to the Furnace Creek and Stovepipe Wells areas of Death Valley National Park, residential lighting from small communities such as Shoshone and Death Valley Junction, vehicles, and minor stationary lighting. Nighttime activities at Briggs Mine may be observed from Panamint Valley and portions of Death Valley National Park overlooking Panamint Valley.

Noise

Vehicle Noise

A high level of traffic is observed along State Highway 127 between Baker and Death Valley Junction (CalTrans 1996). Vehicle noise is generally not an issue in the park in spite of the many and heavily used roads including State Highways 127, 190, and 178, and NPS major paved roads. Because of the park’s size, most areas are well away from traffic and its noise.

Other Sources of Noise

Other areas where localized noise occurs are at the Dumont Dunes off-highway vehicle open area and at mining operations. Less localized is noise from military overflights. Frequent low-level military overflights are often seen in the Panamint and Saline Valleys. If the National Training Center’s (Fort Irwin) expansion is approved, sporadic and significant localized noise would be generated in the southern boundary of Death Valley National Park (BLM 1996).

Overflights

The park is in the vicinity of several U.S. Department of Defense facilities: Fort Irwin Military Reservation, U.S. Naval Weapons Center, China Lake, and Nellis Air Force Base. Military aircraft from these facilities often use airspace in the park. Although aircraft noise does not appear to affect wildlife, visitors to the area often react adversely to jet noise and sonic booms. In addition, some booms have caused damage to natural and cultural resources (NPS 1988).

Military overflights constitute the primary source of high-level noise incidents in the park. Parts of the park are within a joint service restricted airspace complex designated as a military operations area (R2508) that permits aircraft to fly at speeds exceeding 250 knots and at altitudes 200 feet above ground level or higher (DOD 1995). The military operations area is used on a daily basis by Navy and Air Force aircraft. Low-level overflights of various military aircraft are common in the vicinity of the park.

In 1976, Death Valley National Monument and Edwards Air Force Base signed an agreement stating that pilots would be instructed to fly at least 3,000 feet above ground level while within the monument boundary. Jet pilots from the Navy, Marines, Air Force, and the National Guard, fly over 60,000 flights per year from Edwards. Occasionally pilots have erred or ignored flight restrictions and have flown in Death Valley below the 3,000 foot restriction. Upon receiving complaints from the public, the National Park Service will typically notify Edwards on the reported agreement violation.

Title VIII of the California Desert Protection Act, 1994, provides that:

Water

Groundwater

Groundwater is found underneath the park and varies greatly in depth and quality. The park’s groundwater basins are recharged from surface and subsurface infiltration. Depletion of groundwater basins and a diminishing of water quality are some of the concerns that were expressed at public meetings. Groundwater is the park’s principal source for desert springs, seeps, and streams. The maintenance of groundwater quality and quantity is critical to the survival of desert surface waters and their associated plant and animal life.

The major concern is that park water and water-related resources will be affected by up-gradient withdrawals and contamination. Death Valley National Park receives much of its water from the lower portion of the Death Valley groundwater flow system’s flow from Nevada (Pal 1995). The Death Valley groundwater flow system is defined in general terms as the area where groundwater flow is toward Death Valley. Some groundwater inflow also occurs from areas in California that are adjacent to the park. The Death Valley groundwater flow system is believed, by the National Park Service, to be fully, if not over, appropriated. Existing and future appropriations of limited water resources from the flow system may result in impacts to park water resources. Additionally, potentially contaminated groundwater plumes from the Nevada Test Site or from the large cyanide heap leaching mining operation near Bullfrog could affect the regional aquifer that drains into the park (NPS 1988a).

Another site where extensive groundwater is being used at rates that exceed normal groundwater recharge is the Briggs Mine adjacent to the park. The Briggs Mine has an approved mining plan that calls for the groundwater withdrawal of about 640 acre-feet per year (BLM, 1995a). This increase in groundwater withdrawal is in additional to the existing groundwater withdrawal of 750 acre-feet per year from the Panamint Valley (BLM 1995a).

Surface Water

Known surface water sources in the Death Valley region include seeps, wells, springs, and ponds. The small springs and seeps in the park offer isolated and limited water for plants, wildlife, domestic, or commercial purposes. Some springs produce potable water, but overall, water quality is poor because of high dissolved mineral concentrations (BLM 1996).

In 1972, some 330 water sources of varying dependability and quality were recorded within the monument’s boundaries (FWS 1972). The majority of these water sources were found in the Cottonwood, Panamint, and Grapevine mountains. Discharges from these sources range from a minimal seep to rates exceeding 200 gallons per minute. Death Valley’s enlargement to a National Park in 1994 added an additional 1.3 million acres. These new lands include additional water sources such as Darwin Creek, Saline Warm Spring, and many springs in the Nelson Range and Whippoorwill Flat areas of the Inyo Mountains.

Death Valley’s perennial streams include Salt Creek, Cottonwood Creek, and Darwin Creek. The Amargosa River is also perennial, but only for short stretches, with its length varying seasonally. Other streams flow seasonally from springs in some of the larger canyons on the west side of Death Valley, such as in Hanaupah and Johnson canyons (NPS 1988a).

Perennial ponds are rare within the park, and they fluctuate in size with the season. The largest ones (more than 6 acres) are immediately north of Saratoga Springs. Several artificial ponds and ditches supplied by the Travertine Springs are maintained by AMFAC, Inc., on its Furnace Creek properties (NPS 1988a).

Cattle ranching and mining in the desert required changes in the natural water flow, quality, and supply. Flows from springs and seeps were diverted or dammed, water piped miles away from the source, wells were drilled, stock tanks excavated, and other developments were needed such as wind mills and troughs. These changes brought with them changes to the natural environment. When the flows from the springs and seeps were diverted, the remaining aquatic/riparian flora and fauna were greatly reduced or eliminated. The water piped from the springs and seeps or taken from wells and piped to tanks and troughs is used by cattle, burros, and wildlife.

Water Rights

Initial research on outstanding water rights in the park at the State Water Resources Control Board in Sacramento revealed that there are approximately 45 appropriated water rights claims on 41 water sources (springs, seeps, streams, wells) in the park. See "Land Protection Plan" (appendix B) for a complete list.

Guzzlers (Water Catchments)

A guzzler is a permanent self-filling water catchment. Most are similar to a cistern and are simple, low-maintenance devices that are essentially tanks filled by rain-collecting aprons (Giles 1971). Guzzlers are installed and used to provide water for hunted species in arid areas. Nongame species such as reptiles, songbirds, and insects also use these manufactured devices. Birds enter the covered tank through an opening and walk down a ramp to the water. For bighorn sheep, piping extends from the storage tank to a drinking trough, which has a float valve to regulate the flow.

Game numbers have been increased greatly in parts of the arid West by the use of guzzlers (developed by Ben Glading, California Department of Fish and Game) (Dasmann 1964). Professor Dasmann warned that while the guzzler is functioning, animal numbers should be limited to the area’s carrying capacity as "excess numbers of game can easily damage food and cover in areas near water, and in arid lands this damage is long lasting" (Dasmann 1964). This type of damage has been observed in the Mojave Desert near big game guzzlers but not in guzzlers designed for game bird use (McGill, pers. comm., 1997).

Death Valley National Park has five big game and two game bird (gallinaceous) guzzlers. The guzzlers were developed by the California Department of Fish and Game, the Bureau of Land Management, and volunteers prior to the park’s expansion in 1994. A review of guzzler use by park staff concluded that two of the big game guzzlers received little or no use.

Paleontological Resources

Death Valley National Park contains a rich and diverse, but fragile and irreplaceable paleontological record. The fossil record in the park area is nearly as extensive and complicated as the geological record. Much of the area’s geology is exceptionally well exposed. Soil development has been greatly retarded throughout much of the area, and the outstanding exposures of geological features support an equally notable exposure of fossil remains. These organisms have value as (1) stratigraphic indicators for correlation of deposits containing them and for determination of relative geologic age (2) records of past life forms showing the course of evolutionary trends of plants and animals and (3) evidence of changing paleoenvironments.

A literature and records search was completed for the Death Valley National Park region by Robert E. Reynolds, Curator, Earth Sciences, San Bernardino County Museum, Redlands. The records and literature search identified a number of potentially sensitive fossiliferous areas within the park area. Significant paleontologic resources and records relating to paleobiostratigraphic events that occur within the park include:

• The world’s oldest mitosing cells, 990 million years old, are preserved in silica in the Beck Spring Formation.
• Significant Cambrian trilobite and invertebrate fossil localities that mark the boundary of the Paleozoic Era, 550 million years of age.
• Significant occurrences of Paleozoic invertebrate fossils and the possibility of very old fossil fish in Death Valley National Park.
• Panamint Range localities that contain significant marine cephalopods and invertebrate fossils.
• The early record of the Oligocene Tertiary Era from north of the Mojave Desert is found in the Grapevine Mountains in Death Valley National Park; important fossils include rodent, canid, horse, helaletid, brontothere, rhinoceros, oredont, and leptomerycids.
• Extremely important Late Miocene trackways, associated with important vertebrate fossils, occur in the Black Mountains in Death Valley National Park and in the Avawatz Mountains south of the park; the Black Mountains area includes a wide range of camel, horse, gompothere, and aquatic bird trackways associated with a shallow freshwater lakeshore.

Geologic Resources

Death Valley National Park is, geologically speaking, a part of the larger Basin and Range Province. The park’s oldest rocks were formed about 1.8 billion years ago. The weathered sandstone and limestone rocks from the Funeral and Panamint Mountains are much younger, about 500 million years old, and indicate that this area was the site of a warm, shallow sea throughout most of the Paleozoic Era (570–250 million years ago).

About 3 million years ago, the dynamics of crustal movement changed, and Death Valley proper began to form. At this time, compressional forces were replaced by extensional forces. This "pulling apart" of the earth’s crust allowed large blocks of land to slowly slide past one another along faults, forming alternating valleys and mountain ranges. Badwater Basin, the Death Valley salt pan, and the Panamint Mountain Range comprise one block that is rotating eastward as a structural unit. The valley floor has been steadily slipping downward, subsiding along the fault that lies at the base of the Black Mountains. Down-dropping continues today.

Concurrent with the subsidence, has been slow but continuous erosion. Water carries rocks, sand, and gravel down from surrounding hills and deposits the pieces on the valley floor. Beneath Badwater lies over 9,000 feet of accumulated sediments and salts.

Recent signs of volcanic activity exist in the northern third of the park at Ubehebe Crater. Caused by violent steam explosions, the craters formed several thousand years ago when molten material came in contact with groundwater.

There are five dune areas within the park. They are located near Saratoga Springs, Stovepipe Wells, Panamint Springs, Saline Valley, and Eureka Valley. "[The Eureka Valley Dunes are] the highest dunes in the Basin and Range Province and possibly in the United States. When observed at sunset from the west, against the backdrop of the Last Chance Range, its nearly vertical west facing slopes resemble a marvelous parfait-like melange of pink, white and numerous other tones of earth colored rocks" (BLM 1982).

Biological Resources

Vegetation and Wildlife

Exotic Species

Exotic species can include both plants and animals. They are generally defined as those species that occur in a given place as a result of direct or indirect, deliberate, or accidental actions by humans. The exotic species introduced because of such human action would not have evolved with the species native to the place in question and, therefore, would not be a natural component of the ecological system characteristic of that place. Examples of exotic species in the park include wildlife such as burros and chukar and plants like tamarisk and Russian thistle.

Vegetation

Tamarisk, Russian thistle, some palms, introduced annual grasses (from Europe and Asia), and hornwort are some of the more pernicious exotics in the park. These species often outcompete native vegetation, subsequently eliminating or displacing natives and associated native animals. Annual plants, such as introduced grasses and Russian thistle, often provide an unnatural increase in the amount of dried material available as wildfire fuel.

The tamarisk (Tamarix ramossissima), or salt cedar, an introduced shrub or small tree, 5 to 20 feet tall, is an opportunistic invader of moist areas. There are many areas in the park where this plant has choked out native vegetation. Both the Bureau of Land Management and the National Park Service have ongoing control programs that are attempting to manage this invasive plant. Continuing control is needed to prevent this weedy tree from outcompeting and eliminating native vegetation. A larger relative, the athel (T. Aphylla), has been planted, typically as a windbreak or sand-break, in a number of locations in the park (e.g. near Furnace Creek, Death Valley Junction, and Shoshone). Although not as invasive as tamarisk, the athel is also believed to be an invader of native habitats. Death Valley National Park is reducing the potential for reintroduction by encouraging the use of other types of shade trees, landscaping, and windbreak plantings in developed areas within and outside the park.

Russian thistle (commonly called tumbleweed) is common in many disturbed portions of the park, including the Eureka Dunes area, approximately 300 acres near Harrisburg Flats at Skidoo, other old mining sites, and along roadsides.

Date and Washington palms have become established at several backcountry springs in Death Valley National Park. These palms may be removed if it is determined that they are not part of the historical scene.

Introduced annual grasses, such as Bromus and Schismus species, are serious pests when mature (Hitchock and Chase 1971). "The narrow, sharp-pointed minutely barbed florets (or fruits) with their long rough awns work into the eyes, nostrils, and mouths of stock, causing inflammation and offer serious injury"( Hitchock and Chase 1971). The increase of these grasses throughout much of the arid west is believed to be an important contributing factor in the increase in desert wildfires, which used to be uncommon.

Hornwort, an aquatic annual plant with dense growth, is being removed from Saratoga Spring near the southeast boundary of the park (NPS 1988a).

Animals

Aquatics. Death Valley National Park has a number of aquatic exotic species. Mosquito fish, goldfish, crayfish, and bullfrogs are common in the Saline Valley. Mosquito fish are also found at Furnace Creek and goldfish are found at China Garden Spring. Other than the knowledge of their presence, little is known about the effects of these species on the native fauna and flora.

Chukar. The Chukar (Alectoris graeca) an upland game bird, popular among hunters, that was first introduced into California (from India) in 1932 (Mallette c. 1970). Between 1932 and 1955, over 52,000 birds were released by the California Department of Fish and Game (Mallette c. 1970). The birds prefer rocky open hills and flats. Sightings have been reported from below sea level to above 12,000 feet in the White Mountains and Sierra Nevada. The animal is abundant in every valley and mountain range in Death Valley National Park.

Burros and Wild Horses. Burros were used in the Southwest between 1530s, when the Spanish explorers first brought them to North America, until the 1850s, when the discovery of gold in California led to the burro becoming the prospector’s principal means of transportation (Douglas and Leslie 1996). When mines played out or when motorized vehicles became the more practical mode of transport, the miners’ burros were often released into the wild (NPS 1979).

From about 1920 to the 1960s, burro populations were kept at low levels by government agencies like the National Park Service and by the public by organized and random shooting of the burros. These efforts to reduce or eliminate feral burros from national park lands were park managers’ response to the burros damaging park resources and changing the ecological composition at the expense of the park’s native biotic communities.

In the 1950s the states of Arizona and California passed burro protection laws that limited the killing of these animals by private citizens. In the late 1960s, Grand Canyon National Park was prevented by public outcry from continuing the 40-year custom of shooting burros (NPS 1979). In 1971 the Federal Wild Free-Roaming Horse and Burro Act was passed. This act limited the killing of horses and burros on public lands administered by the Bureau of Land Management and the U.S. Forest Service. This law does not apply to NPS lands.

Before the passage of the California Desert Protection Act wild horse numbers were few to none within California desert national park units. Presently, the wild horse numbers within NPS units are low, about 10–20 animals. However, numbers are high in the four BLM herd management areas (HMAs) that are adjacent to Death Valley National Park. In these herd management areas, there are about 305 wild horses (BLM 1995b).

Before the passage of the California Desert Protection Act, the Bureau of Land Management managed 13 herd management areas (HMAs) in the California Desert District. Now the agency manages nine herd management areas, with four former herd management areas now within areas managed by the National Park Service. Of the Bureau of Land Management’s remaining nine HMAs, four are outside the NEMO planning area. The National Park Service agreed to manage new park lands to existing BLM authorized herd management levels until management plans were in place. These management levels are 334 burros and 9 wild horses for Death Valley. The existing burro population levels for the new lands added to Death Valley National Park greatly exceed the BLM herd management levels.

 * BLM 1996 population estimates

Nevada’s BLM Las Vegas Field Office has two herd management areas adjacent to the park, Amargosa and Ash Meadows herd management areas. Both are south of Lathrop Wells, Nevada, and both presently have zero animals and have management levels of zero animals. Other herd management areas within this resource area are at least 6 miles from the stateline. The Bureau of Land Management’s policy is to remove all burros outside of their herd management areas. The Tonopah Resource Area has three herd management areas adjacent to the park. Bull Frog burro HMA, near Beatty, Nevada, has a recommended management level of 53 burros; Gold Mountain burro HMA, between Gold Point and Scotty’s Junction, Nevada, has a management level of zero burros and 50 horses; and Palmetto horse HMA west of Lida, Nevada, which has a management level of 76 horses (BLM 1997). It was reported that about 50 burros exist in the northern portion of Fort Irwin near the Leach Lake area (Steve Ahmann, pers. comm., 1996).

Units of the national park system must be managed under the mandates of the Organic Act of 1916 (16 U.S.C. 1), the 1970 Act for Administration as amended by the 1978 Redwood National Park Expansion Act (16 U.S.C. 1a-1) and the NPS Management Polices (1988). The Endangered Species Act requires that actions by federal agencies do not jeopardize the continued existence of endangered or threatened species or result in adverse modification or destruction of their habitat. It should be reemphasized that the Federal Wild Free-Roaming Horse and Burro Act is not applicable to NPS administered lands (Kleppe v. New Mexico, 426 U.S. 529, 49 l. Ed. 34, 96S. Ct. 2285 (1976)).

Death Valley National Monument was established in 1933. In 1938 there were an estimated 1,500 burros in the monument, occurring in both the Panamint Range on the west and the Amargosa Range on the east side of Death Valley. Burro reduction had started on a limited scale in 1939 and was carried on more extensively between 1958 and 1967. By 1967, 3,570 burros had been removed from the population: 1,790 by live trapping and removal, and 1,780 by direct reduction (shooting). In 1968, due to public sentiment, shooting was discontinued. Although all burros have been removed from the east side of the monument, by fall of 1970, there were an estimated 1,350 in the Panamint Range.

In 1973 the park staff again began live trapping and shooting burros. About 400 burros were shot before discontinuing the practice in 1978.

Death Valley prepared an environmental impact statement in September 1977, which included 20 options for removal of burros. The Death Valley plan meshed with the interim management plans of the BLM’s Bakersfield District, both of which supported NPS policies of removal of exotic species from units of the national park system. A cooperative agreement regarding burro management was drawn up among the Bureau of Land Management, the National Park Service, and China Lake Naval Weapons Center.

The approved plan was conducted in three phases:

An agreement (to conduct the roundups) was made with the Bureau of Land Management and with the animal protection groups. The agreement was signed on July 2, 1982. The three-year roundup began in October 1983. Phase one ended in April 1986, removing alive nearly 6,000 burros. (The 1981 census was 2,501 burros). The government’s cost was $1.7 million. Animal protection groups agreed to take all burros captured out for adoption, but took only 60%.

During phase two from fall 1986 to winter of 1987, 230 burros were removed by animal protection groups. Phase three began on July 1, 1987 and will continue as long as necessary within the old monument boundary.

On February 28, 1995, the superintendents of Death Valley National Park and Mojave National Preserve agreed to an interim management policy for burros on lands formerly managed by the Bureau of Land Management. The policy is to maintain the BLM-approved management levels until a final decision is derived through the formal planning process, which includes the preparation and public review of this document. That level is 297 burros and 9 wild horses for Death Valley National Park and 130 burros for Mojave National Preserve.

The National Park Service estimates that at least 110 burros from Death Valley National Park and 1,100 burros in Mojave National Preserve need to be removed to reach the BLM-approved management levels. Under this interim policy all wild horses and burros removed would be captured and made available for adoption to the public.

In Death Valley National Park the total wild horse and burro populations are about a dozen horses and 350-550 burros. The park’s Nevada triangle boundary, and its southern boundary near Owlshead Mountains are its only areas where there is no adjacent BLM herd management area.

Death Valley National Park is still managing its burros for its former monument boundary under a management strategy developed when it was a national monument. In 1995 a volunteer burro protection group began removing burros via live capture in lieu of the park’s removal policy. The park has not abandoned its existing plans for burro removal within the old monument boundary, but has suspended its own removal plans while the volunteer group’s efforts are underway. This group has removed about 20–30 burros per year. This volunteer operation has been at minimal cost to the federal government, however, it is questionable whether this removal level is helping to reduce the numbers toward zero.

Since many of the herd management areas are adjacent to National Park Service lands, this plan will consider options, developed with Bureau of Land Management and National Park Service interagency cooperation for wild horse and burro management within both NPS units and BLM lands.

Species and Habitats of Special Consideration

Within Death Valley National Park, there are confirmed populations or viable habitat for six federally endangered, one federally threatened, two federally proposed-for-listing, four state endangered, four state threatened, and four state rare plants and animals (see appendix C).

Federally listed species in Death Valley include: desert tortoise (Gopherus agassizii), Devils Hole pupfish (Cyprinodon diabolis), southwestern willow flycatcher (Empidonax trailli extimus), least Bells vireo (Vireo bellii pusillus), Eureka Dunes evening primrose (Oenothera californica ssp. eurekensis), Eureka Valley dunegrass (Swallenia alexandrae), and spring-loving centaury (Centaurium namophilum).

Federally listed species for which final recovery plans exist are desert tortoise, Devils Hole pupfish, Eureka Dunes evening primrose, and Eureka Valley dunegrass. A draft recovery plan is in development for the least Bell’s vireo with a subsequent final plan scheduled for public release in the summer or fall of 1998 (Benz personal communication, 1997).

Federally proposed listed species are: shining milk-vetch (Astragalus lentiginosus var. micans) and Sodaville milk-vetch (Astragalus lentiginosus sesquimetralis).

California listed species, other than those also federally listed or proposed, are: California (or western) yellow billed cuckoo (Coccyzus americanus occidentalis), willow flycatcher (Empidonax trailli), Cottonball Marsh pupfish (Cyprinodon salinus milleri), and Mohave ground squirrel (Spermophilus mohavensis).

California rare plant species, not otherwise federally listed or proposed, are: July gold (Dedeckera eurekensis), and rock lady (Maurandya petrophila).

The species detailed in the text below are: Federally endangered (FE), Federally threatened (FT), Federally proposed threatened (FPT), California Endangered (CAE), California threatened (CAT), or California Rare (CA Rare), Nevada Critically Endangered (NVCE), or Nevada threatened (NVT).

Desert Tortoise (Gopherus agassizii) – FT, CAT

The range of the desert tortoise includes the Mojave and Sonoran deserts in southern California, Arizona, southern Nevada, the southwestern tip of Utah, and Sonora and northern Sinaloa, Mexico. The Mojave population of the desert tortoise (an administrative designation for animals living north and west of the Colorado River) is listed as a threatened species by the Federal government and the state of California. Critical habitat for this species was designated in 1994 (FWS 1994). There is no desert tortoise designated critical habitat within Death Valley National Park. The desert tortoise’s range within Death Valley National Park extends to its southern half. Within the park the current populations (and for at least the last 60 years, are not believed to be very numerous.

The Mojave population of the desert tortoise occurs primarily in valleys and on bajadas characterized by scattered shrubs. The soils range from sand to sandy-gravel, though caliche soils, desert pavement, and rocky, boulder terrain are occasionally used. Desert tortoises spend a large portion of the year underground to avoid extreme temperatures and, for younger tortoises, to avoid a variety of predators, such as coyotes, foxes, raptors, and ravens (BLM 1996). Tortoises are active during the spring, early summer, and autumn when annual plants are most common and daily temperatures are tolerable. Additional activity occasionally occurs during warm weather in winter months and after summer rainstorms (BLM 1996).

Species Addressed in the Ash Meadows Recovery Plan

Devils Hole Pupfish (Cyprinodon diabolis) – FE, NVCE

Devils Hole is a small tract of land administered by Death Valley National Park while part of a larger spring complex in Nevada called Ash Meadows. Devils Hole falls within the boundaries of Ash Meadows National Wildlife Refuge. A limestone cave at Devils Hole, bearing the same name, is the only natural habitat of the Devils Hole pupfish, listed as endangered by the federal government and state of Nevada. The underground aquifer determines the cave’s water level which has no surface outlet. Historic and ongoing mining of groundwater in Ash Meadows has occasionally directly lowered the water level in Devils Hole, occasionally exposing a shallow limestone shelf on which the pupfish depend for food and spawning (Soltz and Naiman 1978; E.P. Pister, pers. comm., 1997).

Decline of the Devils Hole pupfish drove litigation resulting in a U.S. Supreme Court ruling upholding the maintenance of a minimum water level at the cave. From 1980 to at least 1990, the population status was upward but "persistently small and localized." The species is considered not delistable; criteria for its protection are the maintenance of water levels and water chemistry. Other species of special consideration located at the limestone cave or at springs within the 40 acres are: Devils Hole warm springs riffle beetle, Amargosa tryonia snail (Tryonia variegata), (FWS 1990). Water levels are currently monitored by the National Park Service. The combined records from water level monitoring by the National Park Service and the U.S. Geological Survey dating from the 1960s demonstrated a maximum level of recovery in 1989; thereafter, a downward trend has persisted.

The 1990 FWS recovery plan for listed species of Ash Meadows embraced goals of the 1980 recovery plan for the Devils Hole pupfish and addressed the following federally listed species located at Ash Meadows, Nevada, and on National Park Service or BLM-managed areas within adjacent lands in California:

Also noted were Ash Meadows endemics including, but not limited to the following:

 Listed species

Warm Springs pupfish (Cyprinodon nevadensis pectoralis)
Ash Meadows Amargosa pupfish (Cyprinodon nevadensis mionectes)
Ash Meadows speckled dace (Rhinichthys osculus nevadensis)
Ash Meadows naucorid (Ambrysus amargosus)
Ash Meadows blazing star (Mentzelia leucophylla)
Ash Meadows ivesia (Ivesia eremica)
Ash Meadows milk-vetch (Astragalus phoenix)

Other species of concern

Ash Meadows montane vole
white-faced ibis
Amargosa naucorid bug
a host of spring snails (including Amargosa tryonia)
alkali mariposa lily (Calochortus striatus)
Tecopa bird’s beak

Not all of the above-referenced species are directly addressable herein because they are not found on lands within the planning area; they do, however, merit mention due to a common regional water drawdown threat and potential benefits of regional monitoring and conservation. Decline of the listed species at Ash Meadows has been attributed to ground water removal, presence of exotic species and habitat alteration.

The Ash Meadows recovery plan describes "essential habitat" for the Devils Hole and Warm Springs pupfish (the latter found only in close proximity to Devils Hole) and critical habitat as designated for the following plants and animals:

Essential habitat for the Devils Hole pupfish includes "21,760 acres encompassing the area where groundwater removal most influences the water level in Devils Hole."

Although the 1989 General Management Plan for Death Valley National Monument called for a transfer of management for Devils Hole to the U.S. Fish and Wildlife Service, this plan and the recovery plan recommends that the National Park Service retain legal responsibility for the 40 acres under its jurisdiction.

Amargosa pupfish and speckled dace, Amargosa niterwort, spring loving centaury, Ash Meadows sunray, Ash Meadows gumplant, alkali mariposa lily, Tecopa bird’s beak, and white bear poppy range into California at locations along the Amargosa drainage and at various sites supporting stream, spring, salt marsh, moist alkaline soil, calcareous, or riparian habitats.

Riparian-Dependent Bird Species

Mesic habitats in the planning area are not noted for high numbers of the riparian obligates listed above (relative to their known ranges), but such habitats do provide a degree of essential foraging and nesting habitat. To date, other than along the Colorado River, the study of the vireo and flycatcher in the desert have been concentrated along the Mojave River. Small numbers of all three species have been confirmed along the Amargosa River and in Death Valley.

In May 1986, Vireo bellii pusillus was federally listed. Its critical habitat was designated in February 1994. Endangered status took effect for Empidonax trailli extimus in March 1995, and a final determination of critical habitat was made in July 1997. Listing of the willow flycatcher by the state of California is at the species level. Federal recovery planning is underway for both the vireo and flycatcher. There is no critical habitat located within Death Valley National Park for either subspecies.

The western yellow-billed cuckoo, state endangered since 1988, generally requires a broader stand of riparian growth than the vireo or flycatcher, although loss of riparian habitat is the major common factor influencing the decline of all. The cuckoo does not appear to be affected by brood parasitism by the brown-headed cowbird (Molothrus ater) as is a severe problem for the vireo and flycatcher. In this behavior, cowbirds introduce their offspring to the nest and care of a host bird species, competing directly with the success of the host’s young and sometimes eating or ejecting the host’s eggs. (Thelander 1994).

Species Addressed in the Eureka Valley Dunes Recovery Plan

Prior to the administrative transfer to the National Park Service in 1994, the Bureau of Land Management established the Eureka Valley area of critical environmental concern and in 1982, the U.S. Fish and Wildlife Service adopted the Eureka Valley Dunes Recovery Plan. Stemming from these, by draft agreement, a voluntary joint conservation strategy is being developed by the U.S. Fish and Wildlife Service and Death Valley National Park to protect sites where there are four federally listed and proposed plants. The agreement targets actions over entire dune ecosystems to benefit these plants and other species of special consideration including endemic beetles. Two federally endangered species, Eureka Valley evening primrose (Oenothera californica ssp. eurekensis) and Eureka Valley dunegrass (Swallenia alexandrae), and a Federally proposed threatened species, shining milk-vetch (Astragalus lentiginosus var. micans), are only found on dunes within Death Valley National Park. Additionally, the California population of another federally proposed threatened species, Sodaville milk-vetch (Astragalus lentiginosus sesquimetralis), is located at the park (Diane Steeck, pers. comm., 1997).

The largest population of Eureka Valley dunegrass is found on high, unstable areas of Eureka Dunes, with remaining known stands located in smaller dunes on the west side of Eureka Valley. The major occurrence of Eureka Valley evening-primrose is at Eureka Dunes, but this species is also known from two smaller sites on the west side of Eureka Valley, growing on lower slopes and dune flats. Eureka Dunes and one site on the western Eureka Valley comprise the known range of shining milk-vetch, which grows on mid- and lower-dune slopes and some sandy flats. Sodaville milk-vetch has been found at Death Valley National Park and at two sites in Nevada; it relies on margins of alkaline wetlands, near cool springs (Diane Steeck, pers. comm., 1997).

Notable recolonization of shining milk-vetch has occurred in areas where motorized vehicle use is no longer authorized, but concerns remain with occasional motorcycle and other vehicle trespass, vandalism to barriers and signs and other human uses, including sandboarding/skiing and horseback riding. Possible encroachment and competition with the mid- and lower-dune endemics by the nonnative Russian thistle (Salsola sp.) is another concern. It is believed that the most persistent threat to the Sodaville milk-vetch population at Big Sand Spring has been habitat trampling and modification by burros and cattle (Diane Steeck, pers. comm., 1997). This area has been fence by the park to protect the plants.

Other Death Valley National Park Rare Plants

The July gold (Dedeckera eurekensis) and rock lady (Maurandya petrophila grow only in areas containing carbonate soils.

Cottonball Marsh pupfish (Cyprinodon salinus milleri) – CAT

This killifish subspecies is found only in Death Valley, in "portions of Cottonball Marsh on the west side of the central valley floor approximately 5 miles south of Salt Creek" (Death Valley National Monument Draft General Management Plan 1988). Threats to its survival include direct and indirect habitat alteration from changes to water levels, quality, and/or chemistry. An overall concern with regional water diversion is not limited to this species, rather, has the potential to affect a large number of sensitive aquatic species (including insects and snails) and riparian obligates.

Mohave ground squirrel (Spermophilus mohavensis) – CAT

The only known occurrence of the Mohave ground squirrel in the planning area is at Lee Flat, in Death Valley National Park. This represents the northernmost extension of the squirrel’s range, which is limited to the northwestern Mojave Desert. No records exist of traditional or current presence of the squirrel in Panamint Valley nor Saline Valley (Leitner, pers. comm. 1997).

Although previously found in a variety of vegetation associations to 5,600 feet elevation, the species seems to "prefer large alluvial-filled valleys and deep, fine-to-medium textured soils vegetated with creosote bush scrub, shadscale scrub, or alkali sink scrub wherever desert pavement is absent" (FWS 1995a). Winterfat (Krascheninnikovia lanata) and spiny hopsage (Grayia spinosa) are important dietary components; the squirrel favors forbs in wet years and winterfat in dry years. Diets of domestic sheep more closely overlap that of the Mohave ground squirrel than do those of cattle or feral burros (Leitner, pers. comm. 1997).

The species’ state threatened status is based on habitat loss due to agriculture, recreational, and military vehicle use. In 1995, the U.S. Fish and Wildlife Service reviewed a petition to list the species as federally threatened and while advising continued monitoring for impacts due to habitat degradation/ fragmentation and drought, determined a lack of sufficient information to warrant a status review (FWS 1995b; FWS 1995c). Substantial new information is still lacking about recent trends in squirrel populations, historic occupied range, current habitat, and vulnerability of key populations (Gustafson, pers. comm. 1997).

Species Restoration

The National Park Service’s policy is to strive to restore native species to parks. See "Alternatives" section for details on restoration policies and programs. Such programs will be carried out in cooperation with other affected agencies, organizations, and individuals.

Any necessary confinement of animals in small fenced areas during restoration efforts will continue only until the animals have become thoroughly accustomed to the new area or they have become sufficiently established to minimize threats from predators, poaching, disease, or other factors (NPS 1988).