Geologically, the King Range is severely folded and faulted. Three of the large "plates" that make up the earth's crust grind together just offshore. The King Range is at the edge of the North American Plate which is being forced upward from the two offshore plates. These mountains have risen 66 feet in the last 6,000 years. Most of the rock here is graywacke, a dark gray crumbly sandstone. Contrary to popular belief, the Black Sands Beaches are made up of this rock, and are not volcanic in origin.
Offshore rocks, tidepools and kelp beds are inhabited by seals, sea lions and a variety of marine birds. California grey whales can be spotted offshore in winter and spring. The mountains are a mix of Douglas-fir forest, chaparral and grassland, providing habitat for blacktailed deer and black bear. A herd of Roosevelt Elk roams the area from Chemise Mountain south into Sinkyone Wilderness State Park. Curiously, although this is the wettest spot in California, hot dry summer winds make the King Range too dry to support the redwood forests that surround it on three sides.
Nearly 300 species of native and migratory birds have been spotted in the King Range making it a birders paradise. The old-growth forest is important habitat for the northern spotted owl, bald eagle, and coopers hawk.