M332Ba Bitterroot Glaciated Canyons

Landscape Characteristics:

Glaciated mountains with numerous heavily glaciated parallel canyons. The dominant parent material is till derived from quartz monzonite, granodiorite, gneiss, and schist. Elevations range from 4000 to 10000 feet. Drainage density is moderate. Numerous lakes occur in high elevation cirques.

Climate:

Mean annual precipitation ranges from 14 to 70 inches, about 60 percent falling as snow. The soil temperature and moisture regimes are cryic and typic ustic (udic at higher elevations).

Potential Vegetation:

Douglas-fir forest/Western spruce-fir forest

Relationships of Dominant Map Unit Components:

Landform Geology Soil Taxa
Cirquelands/moraines/trough walls Till/talus/granitic rocks Cryochrepts/Cryaquepts
Moraines/terraces/floodplains Till/alluvium Cryochrepts/Cryaquepts/Cryaquents
Dipslopes Granitic rocks Arigborolls/Cryochrepts

Disturbance and Land Use:

The primary natural disturbance is fire. Land use is predominantly wilderness. Some timber harvest and grazing occurs on the eastern dipslope.