Cobblestone Mountain, Mountain summit in Los Padres National Forest, California, US.

Cobblestone Mountain is a summit in the Topatopa Mountains range within Los Padres National Forest, standing at about 6,738 feet in elevation. The peak sits among several ridges and open slopes that rise from forested valleys below.

Cobblestone Mountain lies in the Topatopa Mountains, whose highest summit is Alamo Mountain at 7,402 feet; Cobblestone ranks third at 6,738 feet. The peak stands within the Sespe Wilderness of Los Padres National Forest, about 14 miles north of Piru in Ventura County. Snow frequently falls on the mountain in winter.

Cobblestone Mountain stands within the Sespe Wilderness of Los Padres National Forest, land managed for backcountry travel rather than developed recreation. The peak is the third highest of the Topatopa Mountains, after Alamo Mountain at 7,402 feet, and its upper slopes receive frequent snow in winter. From the east the mountain reads as the most prominent summit of the Alamo Mountain region.

The peak lies in the Sespe Wilderness of Los Padres National Forest, about 14 miles north of Piru, and no trailhead or road access is named in the sources. Snow frequently falls in winter, so check conditions before setting out. The nearest named landmark is Alamo Mountain, 10.5 km away.

Cobblestone Mountain is the most visibly prominent peak of the Alamo Mountain region when the range is viewed from the east. It can be picked out from the Santa Clarita Valley, from higher parts of the San Fernando Valley, on the westbound descent of the Santa Susana Pass on State Route 118, and at Gorman heading south on Interstate 5.