Trout Creek Mountains

Trout Creek Mountains
Disaster Peak and east slope of Trout Creek Mountains
Highest point
Peak	Orovada View Benchmark
Elevation	8,506 ft (2,593 m)
Coordinates	41°58′48″N 118°13′24″W / 41.98°N 118.2232°W / 41.98; -118.2232Coordinates: 41°58′48″N 118°13′24″W / 41.98°N 118.2232°W / 41.98; -118.2232
Dimensions
Length	51 mi (82 km) North-South
Width	36 mi (58 km)
Area	544 sq mi (1,410 km2)
Geography
Country	United States
States	Oregon and Nevada
Geology
Period	Triassic, Cretaceous, and Miocene
Type of rock	Volcanic; uplifted and faulted

The Trout Creek Mountains are a remote mountain range in southeastern Oregon and northern Nevada, United States. The highest point in the range is Orevada View Benchmark. Most of the Trout Creek Mountains are public lands, administered by the Bureau of Land Management. There is very little human development in the Trout Creek Mountains. However, there are grazing allotments that created environmental concerns in the 1980s. The Trout Creek Mountain Working Group was formed in 1988 to help resolve the conflict between livestock owners and environmentalists.

Geology

The Trout Creek Mountains in southeastern Oregon are part of the Basin and Range Province of the Western United States which is characterized by a series of parallel fault blocks forming long north-south oriented mountain ranges separated by wide high desert valleys. The Trout Creek Mountains are uplifted and tilted blocks, with steep escarpments along the southern and eastern sides of the range. The southern area of the range has numerous granitic outcroppings formed during the Cretaceous Period. These outcroppings are commonly found at the base of volcanic ridgelines.^[1]

The Trout Creek Mountains range is composed of basalt from a series of shield volcanoes that once stood where the Steens Mountains are today. These volcanoes began erupting about 17 million years ago, producing a series of lava flows that spread across the land where the Trout Creek Mountains stand today. The eruptions lasted for about one million years. At least seventy separate lava flows occurred. Ultimately, the basalt layers in the Trout Creek area reached a thickness of about 4,500 feet (1,400 m).^[2] However, the Trout Creek Mountains also have much older metamorphic rock underlying the more recent basalt flows. These rocks may be related to some of the Triassic formations of the Blue Mountains Province to the north. These strata have diorite and granodiorite intrusions, probably formed in the Cretaceous Period.^[3][4]

One of the unique geologic features in the Trout Creek Mountains is McDermitt Caldera. The caldera is a collapsed volcanic dome located in the southern part of the range. It was created by volcanic eruptions in the early Miocene, about 19 million years ago. A total of five large ash-flows were produced along with a large rhyolite dome structure. The caldera was formed when the dome collapsed about 16 million years ago.^[5]

Topography

The Trout Creek Mountains cover an area of 511 square miles (1,320 km²) (811 sq mi (2,100 km²) including surrounding lowland areas). The range runs 51 miles (82 km) north to south and 36 miles (58 km) east to west. Most of the Trout Creek range is in Oregon (78%); however, a portion of it extends into northern Nevada. The highest peak in the range is Orevada View Benchmark, which is 8,506 feet (2,593 m) above sea level at its summit. It is located in Nevada, approximately one mile south of the Oregon border. The high point in Oregon is an unnamed ridge summit approximately 2 miles (3.2 km) north of Orevada View. Just two miles south of Orevada View is Disaster Peak, an impressive, symmetrical butte that is visible throughout the region. At 7,781 feet (2,372 m), Disaster Peak anchors the southern end of the range.^[1][6][7][8]

The terrain in the Trout Creek Mountains ranges from broad, flat basins and rolling ridges to high rock escarpments cut by deep canyons. The canyons have steep walls with loose talus slopes below. The rugged ridges are separated by high-desert basins. There are meadows around spring areas, although the Trout Creek range has only a few streams that flow year around. The two largest streams are Trout Creek and Whitehorse Creek, which both drain into dry desert basins.^[1][6][8]

Climate

The Trout Creek Mountains are semiarid due to the dominant weather pattern that moves air east from the Pacific Ocean over the Oregon and California coastal ranges and the Cascade Mountains before passing over the Trout Creek Mountains. This creates a rain shadow effect that condenses most of the moisture in the Pacific air masses before reaching the Trout Creek Mountains. As a result, the average annual precipitation in the Trout Creek area ranges from 8 to 26 inches (200 to 660 mm) per year. Over half of the annual precipitation occurs between the beginning of March and the end of June. Most of the rest falls as snow during the fall and winter months. Snowpack at elevations below 6,000 feet (1,800 m) usually melts by April; however, at the higher elevations, snow often remains until mid-June. Local flooding often occurs in the spring as the snowpack melts.^[9]

The prevailing winds are west-southwest, with the highest winds normally in March and April. Short-duration, high-intensity thunderstorms are common between April and October. Those that occur during the summer months tend to be more isolated and often produce dry-lightning strikes.^[9]

Ecology

Vegetation in the Trout Creek Mountains is dominated by large sagebrush and desert grasses. Other common shrubs include bitterbrush, snowberry, and ceanothus. There are also patches of Mountain mahogany in some areas. Common grass species include Idaho fescue, bluebunch wheatgrass, cheatgrass, western needlegrass, Sandberg's bluegrass, Thurber's needlegrass, and bottlebrush squirreltail plus basin wildrye in some well drained areas.^[9]

Less than one percent of the land is meadow wetlands and riparian greenways. However, these areas are extremely important to the local ecosystem. There are high mountain meadows around springs. Most of the springs occur on gently sloping uplands or in stream bottoms. The meadows range in size from less than an acre (0.4 ha) to more than five acres (2 ha). Narrow riparian greenways follow the year-around streams. Many greenway areas have quaking aspens and willow groves. Cottonwood and alder groves can be found at lower elevations where slopes become flatter and the stream channels are wider. Sedges and rushes are also native to these stream bottoms. Years of heavy livestock grazing in parts of the range resulted in the loss of some grass species and riparian zone plants as well as young aspen and willow trees.^[9]

The wildlife in the Trout Creek Mountains is adapted to the high desert environment. Pronghorn are common in the open, sagebrush covered basins while Mule deer like the cottonwood and willow groves. There are also Bighorn Sheep and cougar in the high country. Jackrabbits and coyotes are common throughout the range.^[10][11][12] Bird species native to the Trout Creek Mountains include sage grouse, Mountain Chickadees, Gray-headed Juncos, Black-throated Gray Warbler, Virginia's Warbler, MacGillivray's Warbler, Pine Siskin, Red Crossbill, Bushtit, Hermit Thrush, and Northern Goshawks, ravens, and eagles.^[12][13]

Several streams in the Trout Creek Mountains have rare Lahontan cutthroat trout. They include Willow Creek, Whitehorse Creek, Little Whitehorse Creek, Doolitle Creek, Fifteen Mile Creek, Indian Creek, Sage Canyon Creek, Line Canyon Creeks, and some tributaries of McDermitt Creek. Lahontan cutthroat trout were listed as an endangered species in 1970; however, they were reclassified as threatened in 1975.^[14]

Human uses

Most of the Trout Creek Mountains are public lands, administered by the Bureau of Land Management. The entire mountain range is very remote. As a result, there are few visitors. Camping, hunting, fishing, hiking, sightseeing and photography are the most popular activities. There are also mining claims and grazing allotments in the mountains.^[1][6]

The Trout Creek Mountains offer a wilderness-like experience. Since there are no campgrounds in the area, overnight visitors must be prepared for wilderness conditions. Hunters come to the area seeking trophy mule deer, antelope, chukars, and rabbits. Trout fishing is permitted on a catch and release basis. The mountains also offer visitors the opportunity to hike on game trail in natural corridors that follow the secluded canyons and creek bottoms or cross-country along the open ridges and rim rocks. There are also Native American petroglyph sites that can be explored; however, these sites are often difficult to find without a guide. Near the Whitehorse Ranch there are miles of trail designated for 4-wheel off-road vehicles.^[1][12]

There are a large number of mining claims in the Trout Creek Mountains. However, mining has been very limited because the mineral deposits found in the area have never been economical to extract.^[1]

Cattle grazing in the Trout Creek Mountains began in the late 19th century. Today, the Bureau of Land Management oversees grazing allotments in the area. As a result of these allotments, cattle can be found grazing in some areas during the spring and summer. Their impact on the local environment was the subject of controversy in the 1980s.^[10]

Trout Creek Mountains Working Group

By the 1980s, a century of heavy grazing had stripped away much of the riparian vegetation that protected stream banks in sensitive greenway areas. As a result, stream banks were eroding and upland vegetation was encroaching into riparian zones. Aspen were rapidly disappearing as young trees were eliminated by grazing cattle. These conditions also put the rare Lahontan cutthroat trout population at risk. Since the Lahontan cutthroat trout is officially designated as a threatened species, environmental group began advocating that grazing permits in the Trout Creek Mountains be cancelled.^[10][15]

As environmentalists pressed the Bureau of Land Management to close much of the Trout Creek range to grazing, frustrated ranchers joined the “sage brush rebellion” seeking to protect their grazing allotments. Initially, it appeared that the issue of grazing in the Trout Creek range would produce prolonged litigation with appeals potentially lasting decades. However, in 1988, a number of interest groups representing all sides of the issue joined together to form the Trout Creek Mountain Working Group. The goal of the group was to find a solution acceptable to everyone, a plan that would protect both the ecological health of the land and the economic well-being of ranchers.^[10][16]

Initial members of the Trout Creek Mountain Working Group included:

Over the next several years the group continued to meet and discuss options for restoring the land without driving local ranchers out of business. All meetings were open to the public.^[16]

The group eventually endorsed a grazing management plan that provided for both the ecological health of sensitive riparian areas and the economic well-being of ranchers. In 1989, the Whitehorse Ranch agreed to rest two grazing allotments totaling 50,000 acres (20,000 ha) to restore critical stream greenways and mountain pastures. The ranch’s allotment on Fifteen Mile Creek was rested for three years and its Willow Creek pasture received a five years rest before grazing was resumed. In addition, the grazing season in mountain pastures was reduced from four months to two, and the total number of cattle released in the allotment areas was reduced from 3,800 to 2,200. Finally, sensitive areas were fenced to protect them from cattle and additional water sources were constructed away from streams. Other ranches also agreed to rest specific pastures including Trout Creek, Cottonwood Creek, and the Whitehorse Butte allotments.^[6][16][17]

In 1991, the Bureau of Land Management approved a new grazing allotment management plan. It was based on the agreements made by the Trout Creek Mountain Working Group. The new plan took effect in 1992. Since then, vegetation in riparian areas of the Trout Creek Mountains have recovered, and studies by the United States Fish and Wildlife Service have verified the Lahontan cutthroat trout population is also recovering.^[6][16]

Cottonwood Creek riparian area before restoration, 1988.	Cottonwood Creek riparian area after restoration, 2002.

References

External links

• Bureau of Land Management, Oregon State Office
• The Aurora Project - Trout Creek Mountains Community Watershed Partnership