The Marin Hills are a series of steep high ridges and peaks in southern Marin County. They are a part of the long Pacific Coast Ranges mountain system. The centerpoint of these hills is the 2,571 foot (784 m) Mount Tamalpais near Mill Valley. The hills are bordered to the north by the Santa Rosa Plain and Laguna de Santa Rosa; to the east by San Pablo Bay, the northern arm of San Francisco Bay; to the south by Golden Gate Strait; and to the west by the San Andreas Fault, running through Tomales Bay, Olema Valley, Bolinas Lagoon, and Stinson Beach. Parts of the hills are protected for their scenic beauty by Mount Tamalpais State Park and the Golden Gate National Recreation Area.