Level IV: (4b) Western Cascades Montane Highlands
The Western Cascades Montane Highlands ecoregion is characterized by steeply sloping, dissected mountains with high to medium gradient streams and glacial rock-basin lakes. Elevation varies from 3,000 and 6,500 feet (914 to 1,981 m).
The western Cascades are older and more eroded than the lava plateau and prominent snow-covered cones of the High Cascades to the east. They are underlain by dark basalt in contrast to the gray andesite of the High Cascades. The region has lower temperatures and receives more winter snow than the lowlands and valleys to the west. Soils have a frigid or cryic temperature regimes.
Abundant precipitation supports forests dominated by Douglas-fir and western hemlock, with mountain hemlock, noble fir, subalpine fir, grand fir, Pacific silver fir, red alder, and Pacific yew, and an understory of vine maple, rhododendron, Oregon grape, huckleberry, and thimbleberry.