It is part of the larger grouping known as the Pacific Coast Ranges that extends over much of the western edge of North America from California to Alaska.

The mountains are home to a variety of wildlife including black bear, elk, deer, beaver, many species of birds, and bats among others.

Fish, including salmon and trout, and other aquatic life inhabit the streams and rivers flowing through the range.

Volcanic activity approximately 66 million years ago in the Cretaceous Period created offshore islands beginning in the southern portion of the current range.

[1] These deposits offshore were then pushed into the continental plate as a forearc basin rotating slowly over millions of years.

[1] Additional basalt flows originated from Eastern Oregon and added to the layers that were uplifted, as the newer Cascade Mountains had not yet been formed.

[1] By the Early Oligocene period c. 30 million years ago the current coastline was in place and erosion has continued to shape the range.

[1] The geologic boundaries of the coast range formation extend from southwest Washington state in the north to around the Coquille River in the south where the older and taller Klamath Mountains begin.

A mild maritime climate prevails throughout the range with temperature and precipitation varying due to elevation and distance from the coastline.

[3] This shields the Willamette Valley and causes a less maritime climate with hotter summers and less precipitation than the Oregon Coast.

[7] Other plants include huckleberry, salmonberry, salal, vine maple, Oregon grape, bracken fern, and thimble-berry among others.