Coast Range (EPA Ecoregion)

The Coast Range ecoregion is a Level III ecoregion designated by the Environmental Protection Agency (EPA) in the U.S. states of Washington, Oregon, and California. It stretches along the Pacific Coast from the tip of the Olympic Peninsula in the north to the San Francisco Bay in the south, including Grays Harbor, Willapa Bay, and the Long Beach Peninsula in Washington, the entire length of the Oregon Coast, and the Northern California Coast. Named for the Coast Range mountains, it encompasses the lower elevations of the Olympic Mountains, the Oregon Coast Range, the Californian North Coast Ranges, and surrounding lowlands.

The low mountains of the ecoregion are covered by highly productive, rain-drenched evergreen forests that are home to the three tallest conifer species in the world: Coast redwood, Coast Douglas-fir, and Sitka spruce. Historically, Sitka spruce forests dominated the fog-shrouded coast, while a mosaic of western redcedar, western hemlock, and seral Douglas-fir blanketed the inland areas. Today, Douglas-fir plantations are prevalent on the intensively logged and managed landscape. Lithology influences land management strategies; slopes underlain by sedimentary rock are more susceptible to failure following clearcutting and road building than those underlain by volcanic rock.

The Coast Range ecoregion has been subdivided into fifteen Level IV ecoregions.