Cow Mountain is a ridge in the Mayacamas Mountains in Lake County, California, and Mendocino County, California. It is home to two large recreation areas. One is closed to off-road vehicles and the other is not. Erosion from the mountain, caused in part by human land use, contributes sediment and nutrients to Clear Lake.

The Mayacamas Mountains are located in northwestern California in the United States. The mountain range is part of the Northern Inner Coast Ranges, of the California Coast Ranges System.