Cobb Mountain, the highest peak in California’s Mayacamas range at 4,723 feet, rises in Lake County near the town of Cobb and includes a southwest sub-peak that is the highest point in Sonoma County. Its volcanic landscape, winter snowfall, and multiple watersheds make it a prominent natural feature, while much of the mountain also lies within The Geysers geothermal field. Despite its importance, most of the mountain is inaccessible because it is held by geothermal plants, spring-water properties, or private timberland. Named for pioneer settler John Cobb, the mountain and nearby community were heavily damaged in the 2015 Valley Fire, which began there.