Ochoco Mountains


The Ochoco Mountains are a mountain range in central Oregon in the United States, located at the western end of the Blue Mountains. They were formed when Permian, Triassic, and Jurassic rocks were slowly uplifted by volcanic eruptions to form the Clarno Formation. Today, the highest point in the range is Lookout Mountain. The dominant vegetation on the west side of the range is old-growth ponderosa pine; on the east side, western juniper is common. The western area of the mountains is administered by the Ochoco National Forest, while the southeastern section is part of the Malheur National Forest. The Ochoco Mountains are used for hiking, camping, bird watching, rockhounding, and hunting, as well as cross-country skiing in the winter.

Geography

The Ochoco Mountains run north to south and east to west. The eight highest peaks in the range are:
The Ochoco Mountains in central Oregon form the western end of the Blue Mountains province. The Blue Mountains are not a single cohesive range, but rather a complex of ranges and inter-mountain basins and valleys that extend from southeast Washington into central Oregon, ending near Prineville. The Ochoco portion of the province is part of a wide uplifted plateau made of rocks from the Permian, Triassic, and Jurassic periods that were transported by the Pacific Plate and accreted in the late Mesozoic era as part of a vast shallow sea, then slowly uplifted by volcanic eruptions during the Eocene epoch to form the Clarno Formation. From 37 to 17 million years ago, eruptions in the western Cascade Range spread ash across eastern Oregon, forming the John Day Formation. From 17 to 14 million years ago, major volcanic eruptions covered much of the province with basalt flows, creating the Columbia River Basalt Group. Since then, continued faulting and uplift has resulted in a deeply eroded landscape. Steins Pillar is an excellent example of this erosion.
During the Eocene epoch, central Oregon volcanoes deposited layers of lava and ash up to thick over the area that is now the Ochoco Mountains. Large mudflows called lahars were also common during that period. These mudflows often covered and preserved the plants and animals, resulting in fossil beds. Today, fossils of prehistoric trees, fruits, nuts, and flowers can be found in the Ochoco Mountains along with fossilized animals including horses, camels, rhinoceros, and hippopotami.

Ecology

The vegetation in the Ochoco Mountains ranges from old-growth ponderosa pine on the western slopes and in the mountain valleys to western juniper and sagebrush on the eastern and southern slopes. The high mountain meadows host a wide variety of wild flowers and even ferns in some areas. Big Summit Prairie near the center of the Ochocos is well known for its spring wild flower displays.
Ponderosa pine is the dominant tree species in most parts of the Ochoco Mountains. These pines are common at elevations from above sea level. Manzanita, antelope bitterbrush, and ceanothus are common shrubs in the pine-dominated areas with Idaho fescue and Ross' sedge as the main ground cover. Ponderosa pine forests are tolerant of drought and low-intensity wildfires. Birds commonly found in the pine forests of the Ochoco Mountains include the northern flicker, hairy woodpecker, red-tailed hawk, and Steller's jay. Central Oregon's ponderosa pine forests are an important winter range for mule deer and Rocky Mountain elk.
On the drier, eastern side of the Ochoco Mountains, the western juniper trees survive on as little as of precipitation per year. The range's juniper woodlands cover wide areas from in elevation. Antelope bitterbrush and sagebrush are common shrubs in these areas with Idaho fescue and bluebunch wheatgrass as the main ground cover. Juniper woodlands are home to mountain bluebirds, Townsend's solitaires, and ferruginous hawks during the spring and summer. There are also many small mammals and lizards that are prey for coyote.
Big Summit Prairie is a large high-country meadow covering in the middle of the Ochoco Mountains. The prairie is covered by water-loving grasses, overgrown by willows and shrubs in some areas. Tufted hairgrass, elephant's head, and horsetail are common ground cover in the meadowlands. Quaking aspen with shrubby undergrowth attract wildlife not found in other parts of the Ochoco Mountains. Common birds include sandhill crane, Wilson's snipe, long-billed curlew, and northern harrier. Even the rare dickcissel has been sighted at Big Summit Prairie. Larger animals include mule deer, pronghorn, Belding's ground squirrel, northern pocket gopher, meadow mice, and coyotes. Also, Rocky Mountain elk move into the area in the fall.
Big Summit Prairie is particularly well known for its wildflowers and butterflies. From April through June, flowers cover Big Summit meadow. The first wildflowers to bloom are usually grass widow, wild parsley, and shooting stars. From May through June, Wyethia, buttercups, and camas display their colors. In drier areas, bitterroot bloom with large white and pink flowers. In June and July, other flowers take over the display including Missouri iris, larkspur, Indian paintbrush, checkermallow, and arrowleaf balsamroot. One notable plant is Peck's mariposa lily, a type of Calochortus with lavender petals. This plant is found only in the Ochoco Mountains. Butterfly species common to the Big Summit Prairie include hairstreak, skipper, eastern tailed-blue, Lycaenidae, checkerspot, fritillary, swallowtail, admiral, and tortoiseshell.

Human uses

Most of the Ochoco Mountains are public lands administered by the United States Forest Service. The Ochoco National Forest is responsible for most of the mountain area; however, the southeastern part of the range is in the Malheur National Forest. Some land in the Ochoco area is also administered by the Bureau of Land Management. Hiking, fishing, camping, hunting, horseback riding, bird watching, and rockhounding are all popular activities.
The Ochoco National Forest maintains 27 campgrounds in or near the Ochoco Mountains. The largest are the Antelope Flat Reservoir, Ochoco Divide, Walton Lake, and Wildcat campgrounds. The Malheur National Forest has several campgrounds in the Ochoco Mountains as well. The largest is the campground at Delintment Lake.
The unique geology of the Ochoco Mountains is such that a wide variety of rock types are located in a relatively small area. This brings rockhounds to the area every summer. The Bureau of Land Management and the Ochoco National Forest both have designated areas where rockhounds can search for agate, jasper, petrified wood, petrified moss, and dendrite. These rock collection sites are for personal use only; gathering rocks for commercial purposes is prohibited. Thundereggs can be found at Whistle Springs. Even though the area has been worked by rockhounds for many years, quality thundereggs are still found at the site. There are also some rare rocks and minerals in central Oregon in or near the Ochoco Mountains, including opals, amethyst, gem quality calcite, cinnabar, selenite, gypsum, and amygdaloid nodules.

Wilderness areas

The Ochoco National Forest has three wilderness areas in the Ochoco Mountains. They are the Bridge Creek Wilderness, the Black Canyon Wilderness, and the Mill Creek Wilderness.