M333Da Coeur d'Alene Mountains

Landscape Characteristics:

Faulted, low relief mountains formed from quartzite, argillite, and siltite. Some basalt occurs on the western edge of the subsection and granitic rocks occur on the east and north sides of Hayden Lake and on the south end of Lake Pend Oreille. Alpine glaciation has shaped the upper one-quarter of most drainages. Volcanic ash influences most surface soils. Elevations range from 2150 to 6500 feet. Drainage density is moderate. Hayden, Fernan, Coeur d'Alene, and Pend Oreille lakes occur in or directly adjacent to this subsection. Lakes also occur in a few of the high elevation cirque basins.

Climate:

Mean annual precipitation ranges from 20 to 75 inches, about 70 percent falling as snow. The soil temperature and moisture regimes are frigid (cryic at higher elevations) and udic.

Potential Vegetation:

Cedar-hemlock-pine forest with some Douglas-fir forest at higher elevations.

Relationships of Dominant Map Unit Components:

Landform Geology Soil Taxa
Mid-elevation mountain slopes/ridges Quartzite/siltite/argillite Udivitrands/Dystrochrepts
High-elevation mountain slopes/ridges/cirques Quartzite/siltite Haplocryands/Fulvicryands/Cryochrepts/Dystrochrepts
Valley floors/terraces/fans Alluvium Aquands/Cryands/Aquepts/Boralfs

Disturbance and Land Use:

The primary natural disturbances are fire, insects, disease, and flooding. Land uses include intensive timber harvest, rural and suburban development, and heavy mining and smelter operations in the Silver Valley.