Pedro Mountain Road, Mountain hiking trail in Pacifica, United States.

Pedro Mountain Road is a hiking trail that runs through the ridgelines between Pacifica and Montara over a multi-mile distance. The route crosses varied terrain with different surface conditions and steady elevation changes throughout its length.

The road originally served as a main route between Colma and Half Moon Bay until 1937, when State Highway 1 was completed. This new highway drew traffic away from the older mountain road, which gradually transformed into a recreational path.

Cyclists unofficially call the old roadbed "Planet of the Apes." The route is shared by hikers, mountain bikers and horses, and a chain-link fence marks the surviving stub in Montara near the local nursery. The trail continues past Martini Creek to the ranger's residence and on to Saddle Pass.

The trail entrance is located at Higgins Way in the Linda Mar neighborhood with gradual uphill sections that become steeper in places. Conditions can vary by season and weather, so come prepared for different ground surfaces and elevation gains.

Cyclists unofficially call the old road "Planet of the Apes." Wrecked cars from the Half Moon Bay–Colma Road era still lie in the ravines below the route, where grades reached 24 to 25 percent and a sign warned: "DANGEROUS FOR AUTOMOBILES—TAKE ROAD VIA SAN MATEO."