Antiaircraft defenses on Wolf Ridge


Wolf Ridge, a rugged spine of coastal grassland and low chaparral, is the divide between the Rodeo and Tennessee Valleys in the Marin Headlands. In the years leading to World War II the “1937 Project for the Harbor Defenses of San Francisco” led to the formation of Fort Cronkhite and the construction of Battery Townsley with its massive 16” guns. The maturation of military aviation in the two decades since World War I caused fundamental changes in coastal defense. Coastal artillery needed the concealment and cover provided by casemated construction and antiaircraft guns were positioned to defend the batteries.

Marin Headlands - Wolf Ridge

Wold Ridge – downtown San Francisco is visible on the far horizon.

Wolf Ridge was the location of Antiaircraft Battery No. 1 consisting of three 3″ Antiaircraft Gun Model M1917 and their mounts, a storeroom, a power plan and aiming stations. In a 1993 assessment, the GGNRA concluded that Antiaircraft Battery No. 1 is the finest surviving example of an antiaircraft artillery emplacement of the World War II era in the system of seacoast defenses that protected the San Francisco Bay area.

Marin Headlands - Wolf Ridge

A view toward Battery Townsley and the entrance to the Golden Gate Straight.

While hiking along Wolf Ridge one encounters remnants of defensive positions, some quite modest, that still convey the sense of urgency that must have dominated preparations precipitated by the attack on Pearl Harbor. An attack on the West Coast was not out of the question. Along the ridge are several gun positions constructed by stacking hundreds of cement bags. I imagine, but have not confirmed, that these held 50-caliber machine guns. Elsewhere there are level platforms for larger guns.

Marin Headlands - Wolf Ridge

One of several guns positions contracted by stacking cement bags.

The aiming and command center for the antiaircraft guns is located about a thousand feet east of the gun positions. It appears that the facility was hastily constructed – large trenches dug, rooms framed (at least one as a quonset hut), and then the network of rooms and tunnels covered with a backfill of earth leaving a height finding station and director pit at the surface. Some of the underground rooms were quite large, on the order of 13’ by 60’. These were camouflaged and the director pit, location of a mechanical gun director computer, featured a sliding roof.

Marin Headlands - Wolf Ridge

Ruins of the command center.

The command center is now in ruin. The underground rooms have partially collapsed. The earth cover has washed away to reveal some of the tunnels that allowed underground circulation and access to the surface aiming stations. Portions of the site have traces of fencing that I think date from the Nike Missile era.

Photographing Wolf Ridge was difficult. The winds were turbulent and I had my first real camera crash in several years (damage easily repaired). I plan to return and shoot it again.

Here is a set of images from the session that I have posted to Flickr:




I am taking these aerial photographs as a volunteer with the Golden Gate National Recreation Area. For more information see

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