Rugged high mountains are the dominant feature. Elevation varies from 1300 to 8000 feet. Shrubs, forbs, and grasses represent forest understory vegetation. Perennial and ephemeral streams are usually high gradient and fast flowing. Stream density can range from less than one to as many as three miles of perennial stream flow per square mile.
Lakes are common in higher glaciated areas.
Both the Boise and Payette National Forests lie within part of this area. Timber harvest is the major economy, but wildlife habitat, recreation and mining are also important land uses. The multiple use of these forests provide diverse habitat types for scientific study. In a 3-4 hour drive to the northwest, the Blue Mountains ecoregion begins. Elevation varies from 2700 feet in low lying valleys to 7000-10,000 feet on mountain peaks.