The Low Olympics ecoregion contains foothills and lower mountains of the Olympic Range, with U-shaped valleys and high gradient streams. It rises to an elevation of approximately . Higher areas were glaciated. Copious precipitation (up to a year) supports a lush, epiphyte-rich rainforest of western hemlock, western red cedar, and Douglas-fir, with Pacific silver fir at higher elevations. Riparian zones support red alder and bigleaf maple forests. Much of the region is in the third rotation of logging, including land within the Olympic National Forest. However, a portion of the region lies within Olympic National Park and contains ancient forests with extremely high biomass. The region covers , entirely on the Olympic Peninsula of Washington. The higher elevations of the Olympic Mountains to the east are designated as part of the North Cascades ecoregion.