M333Dd North Idaho Hills and Valleys

Landscape Characteristics:

Hills and low relief mountains the formed dominantly from quartzite, argillite, and siltite. Intrusions of Idaho batholith granitics and Columbia River basalts also occur. Volcanic ash influenced loess covers much of the area. Elevations range from 2200 to 5500 feet. Drainage density is moderate to high.

Climate:

Mean annual precipitation ranges from 30 to 55 inches, about 60 to 70 percent falling as snow. The soil temperature and moisture regimes are frigid and udic in the east half of the subsection, grading to frigid and typic xeric in the west half. Cryic temperature regimes occur at high elevations.

Potential Vegetation:

Cedar-hemlock-pine forest/Western ponderosa forest

Relationships of Dominant Map Unit Components:

Landform Geology Soil Taxa
Valley floors/fans/terraces Alluvium Vitrands/Aquands/Aquepts/Boralfs
Hills/low mountains Loess Udivitrands
High elevation slopes/ridges Loess Haplocryands/Fulvicryands

Disturbance and Land Use:

The primary natural disturbances are fire, insects, disease, and flooding. Land use is predominantly intensive timber harvest, rural/suburban development, farming/ranching, and mining.