The Northern Rockies region includes 15 national forests, nearly 20 wilderness areas, and 3 national parks across the U.S. Forest Service Northern Region and the adjacent Greater Yellowstone Area. The area spans northern Idaho, Montana, northwest Wyoming, North Dakota, and northern South Dakota.
The Vulnerability and Adaptation project addresses 5 subregions:
- Western Rockies: Idaho Panhandle NF, Kootenai NF, Nez Perce-Clearwater NF, Glacier NP
- Eastern Rockies: Beaverhead-Deerlodge NF (eastern portion), Custer NF (eastern portion), Gallatin NF (northern portion), Helena NF, Lewis and Clark NF
- Central Montana: Bitterroot NF, Flathead NF, Lolo NF
- Grasslands: Custer NF (part), Dakota Prairie NG
- Greater Yellowstone Area: Bridger-Teton NF, Caribou-Targhee NF, Shoshone NF, Gallatin NF (southern portion), Custer NF (western portion), Beaverhead-Deerlodge NF (western portion), Grand Teton NP, Yellowstone NP
Climatological gradients contribute to the ecological diversity found within the region. The western portion of the area is influenced by the warm and wet maritime airflows from the Pacific Ocean. In contrast, the eastern portion of the region is dominated by cooler and drier airflows from Canada. As a result, annual precipitation can be upward of 200 cm in northern Idaho and as low as 20 cm in central and eastern Montana.
These broad climatological differences, together with local geologic variation, form the basis of ecological diversity. In the western portion of the region, coniferous forests dominate; common species include ponderosa pine, Douglas-fir, grand fir, western redcedar, western hemlock, lodgepole pine, subalpine fir, Engelmann spruce, and whitebark pine. At the extremes, ponderosa pine is typically in low elevation, warm and dry locations, whereas whitebark pine, subalpine fir, and Engelmann spruce are in cold, high elevation locations. Moving eastward into drier areas across Montana and into the Greater Yellowstone Area, ponderosa pine, Douglas-fir, and lodgepole pine are more common. In eastern Montana and the Dakotas, the region’s driest area, the occasional ponderosa pine stand transitions to bur oak and prairie grasslands.
In addition to ecological diversity, hydrology, fisheries, wildlife, and recreation are important resource values for the region. In the western portion of the region, steep mountains streams, including the headwaters to the Snake-Columbia, Colorado- Green, and Missouri-Mississippi, support diverse fisheries. To the east, wetlands are prevalent and contribute to fish and avian diversity. Utilizing aquatic and terrestrial habitats, the region’s wildlife includes black bear, grizzly bear, bobcat, Canada lynx, mountain lion, coyote, gray wolf, red fox, swift fox, bison, bighorn sheep, mountain goat, elk, mink, black-footed ferret, fisher, and wolverine.
The socio-economic foundation of the region is based on these natural resources. The geographic and ecological diversity of the region, especially on national forest and national park land, contribute to a robust recreational industry. Population centers are distributed around resource-based activities, including timber, agriculture, grazing, and energy production. These economic and natural resources inform management decisions throughout the region.