It differs from the Coast Range ecoregion designated by the Environmental Protection Agency of the United States in that it includes the entirety of Vancouver Island and excludes the coastal forests of Northern California.

North of the Chehalis River Valley of Washington state, the ecoregion features a predominantly oceanic climate (Köppen Cfb) with cool winters, mild summers, and plentiful rainfall throughout the year.

South of the Chehalis River Valley and along the east coast of Vancouver Island, the ecoregion has a predominantly Mediterranean climate (Köppen Csb) with fresh, dry, sunny summers and cool winters with moderate precipitation and plentiful cloud cover.

The driest areas in eastern Vancouver Island consist of mixed stands of Douglas fir and western hemlock with occasional Garry oak, Pacific dogwood and arbutus.

Occasional grasslands, sand dune and strand communities, rush meadows and marshes, and western red cedar and alder swamps break up the conifer forests.

Characteristic wildlife include Roosevelt elk, black-tailed deer, black bear, coyote, beaver, raccoon, mink, grouse, and a variety of migratory seabirds and waterfowl.