M333Bc Flathead River Valley

Landscape Characteristics:

Intermontane basin that formed in alluvium, glacial outwash, and lacustrine sediments underlain by argillite, siltite, and dolomite. Elevations range from 2300 to 4500 feet. Drainage density is low to moderate.

Climate:

Mean annual precipitation ranges from 14 to 25 inches, about 50 percent falling as snow. The soil temperature and moisture regimes are frigid and typic xeric.

Potential Vegetation:

Foothills prairie/Western ponderosa forest

Relationships of Dominant Map Unit Components:

Landform Geology Soil Taxa
Floodplains/terraces Alluvium Haploxerolls/Ustifluvents/Haploborolls
Foothills/moraines Lacustrine sediments/outwash Xerochrepts/Ustochrepts/Ustipsamments

Disturbance and Land Use:

The primary natural disturbances are fire and flooding. Land use is predominantly agriculture, rural/suburban development, and some timber harvest.