Miles-Rock

Chris J LeBlanc Photography - Lighthouses

Providing details and historical information of lighthouse pictures taken during my travels

Miles Rock Lighthouse

San Francisco, California

Location: Located on the south side of the entrance to San Francisco Bay west of the Golden Gate Bridge.

Latitude: N 37.79282

Longitude: W 122.510375

Year Constructed: 1906 (James A. McMahon). Active

Tower Height: 35 feet Focal Plane: 49 feet

Circular 1-story steel building mounted on a massive stone caisson, painted with red and white horizontal bands; rotating aerobeacon.

Historical Information:

This lighthouse was completed in 1906, after considerable difficulty caused by the heavy seas and strong currents occurring at this point. The rock upon which the lighthouse is built measured only 40 by 30 feet at high water. The base of the tower is a large block of concrete protected by steel plating. Steel and concrete in the foundation alone weighed 1,500 tons. The superstructure is of steel, and houses the fog signal apparatus and the quarters for the keepers, with the lantern above. It was on this rock that the Rio Janeiro was wrecked shortly before the building of the lighthouse. One hundred and twenty-eight persons out of a total of 209, lost their lives when the Rio Janeiro went down on February 2, 1901. The wreck has never been found. In 1966, the tower was removed, and the light automated.

The southern side of the entrance to the Golden Gate is dotted with a family of dangerous wave-swept rocks. In November of 1889, the Lighthouse Service placed a bell buoy near the rocks. However, the strong currents in the area would pull the buoy beneath the surface of the water and even set it adrift. A tragic wreck provided ample motivation to overcome the obstacles inherent in constructing a lighthouse atop Mile Rock.

A good portion of Mile Rock, which measured 40 by 30 feet, was blasted away to provide a level foundation. Next, four-feet thick walls made of steel-reinforced concrete were built to a height of thirty-five feet to form the base of the tower. A cistern and fuel tanks were located within the base, with a heavy door at the base providing access for refueling. Atop the caisson, a three-tiered steel tower, capped by a lantern room, was constructed. the lantern room with its crosshatched window panes protected a third-order Fresnel lens, which was first lit during the winter of 1906.

In 1966, the Coast Guard dismantled the lantern room and top two tiers of the lighthouse and constructed the landing pad. Although the base of the tower is now painted with colorful orange and white bands, the beauty of the structure was greatly compromised when the tower was decapitated.