Section M332D Belt Mountains
Geomorphology. This Section comprises high mountains, gravel-capped benches, and intermontane valleys bordered by terraces and fans. Plains and rolling hills surround the isolated mountain ranges. Elevation ranges from 4,000 to 8,500 ft (1,220 to 2,593 m) in the mountains; elevation ranges from 2,500 to 5,000 ft (763 to 1,525 m) on the plains. Most of this Section is within the Northern Rocky Mountains physiographic province, but the eastern part extends onto the Missouri Plateau within the Great Plains physiographic province.
Lithology and Stratigraphy. There are Paleozoic and Precambrian metamorphic and Cretaceous soft sedimentary rocks.
Soil Taxa. Frigid and cryic Ochrepts, Boralfs, and Borolls occur in the mountains. These soils are shallow to moderately deep with loamy to sandy textures. Frigid Orthents, Borolls, and Fluvents occur on the plains. These soils are generally moderately deep to deep with loamy to clayey textures.
Potential Natural Vegetation. Kuchler classified vegetation as foothills prairie (75 percent) and Douglas-fir forest--eastern ponderosa forest (25 percent). Forests are associated with prominent mountain ranges and the Missouri River breaks, and cover all but the highest peaks. Typical prairie species include wheatgrasses, fescues, grama, and needlegrass. Common tree species are Douglas-fir, ponderosa pine, limber pine, and subalpine fir.
Fauna. Birds are typical of short-grass prairie or the drier portions of the Rocky Mountains. Species of note are ferruginous and Swainson's hawks, golden eagle, prairie falcon, sage grouse, Lewis' woodpecker, western kingbird, horned lark, yellow-rumped warbler, and lazuli bunting. Several birds near the extent of their range in this Section, including both eastern and western screech-owls, calliope hummingbird, red-headed woodpecker, mountain chickadee, Sprague's pipit, ovenbird, and McCown's longspur. Typical herbivores and carnivores include white-tailed deer, mule deer, elk, moose, black bear, bobcat, and cougar. Smaller common herbivores include the snowshoe hare and northern flying squirrel. Rare species include the northern bog lemming. Herpetofauna typical of this Section are the spotted frog, Pacific treefrog, western toad, and long-toed salamander.
Climate. Precipitation ranges from 10 to 40 in (250 to 1,020 mm), with maximum precipitation occurring in spring and early fall; winter precipitation is snow. Climate is cold continental. Temperature averages 36 to 45 F (2 to 7 C). Temperature extremes are common throughout the winter months; strong winds are common throughout the year. The growing season ranges from 45 to 140 days.
Surface Water Characteristics. Perennial streams have a dominantly dendritic drainage pattern and are fairly widely spaced. Some drainages are deeply incised as they leave the mountains. Holter and Canyon Ferry lakes are in this Section. Smaller lakes occur at higher elevations. Major rivers include the Missouri and the Smith.
Disturbance Regimes. Fire, insects, and disease are the principal natural sources of disturbance.
Land Use. Land uses are dominantly livestock grazing, timber harvest, watershed, wildlife habitat, and recreation.
