Fort Cronkhite is a historical U.S. Army facility that supported Battery Townsley, part of the coastal artillery defenses of San Francisco Bay on the Marin Headlands during World War II and now part of the Golden Gate National Recreation Area, about 8 miles (13 km) southwest of Stinson Beach and 8 miles (13 km) west-northwest of San Francisco, California. The Marin Headlands form the southern tip of the Marin Peninsula and consist of geological formations created by the accretion of oceanic sediments from the Pacific Plate onto the North American Plate. The primary rock types of the Marin Headlands include greywacke sandstone, radiolarian chert, serpentinite, pillow basalts, and shale. These are part of a rock formation called the Franciscan Complex that has migrated north along the San Andreas Fault over the last 100 million years from an area near present-day Los Angeles. The Coast Miwok were a people that inhabited the Marin Headlands for thousands of years prior to European contact. Before colonization, the Coast Miwok freely moved between the bay side of the peninsula and the ocean side. In 1776, when Spanish military and civilian settlers arrived in the San Francisco bay area to establish military garrisons, Franciscan missions, and civil settlements, most of the Coast Miwok moved to the mission at San Franciso and were converted to Christianity. Coast Miwok are now a federally-recognized tribe called the Federated Indians of Graton Rancheria. After the Mexican War of Independence in 1821, the lands held by Spanish missions were secularized and granted to individuals as private ranchos. In 1838, a Mexican land grant of 19,752 acres (7,993 ha) called Rancho Saucelito was given by Governor Juan Alvarado to Captain William A. Richardson. The name means ‘ranch of the little willow grove’. The grant extended from the Pacific Ocean on the west, to Mount Tamalpais to the north, and the Arroyo Corte Madera del Presidio and Richardson Bay on the east.  Richardson made a series of poor investments and ended up in debt to many creditors. In 1856, ailing in health and finances, Richardson put the estate into the hands of Samuel R. Throckmorton. Throckmorton sold off parcels to settle debts, and lands north of Rodeo Lagoon were eventually owned by the Marin Land and Cattle Company that operated a dairy farm. The Marin Headlands have an ideal climate for raising dairy cows and once supported many prosperous dairies. By the 1880s, Marin County was California’s largest producer of fresh milk and butter. Much of this success was based on the labor of Portuguese immigrants from the Azores, mostly the island of Saint George. This land was located on the north shore of the entrance to San Francisco Bay and military planners realized the strategic defense value of the location overlooking the Golden Gate.

In 1866, lands on the Marin Headlands were acquired for Forts Baker and Barry by purchase and to be used for military defense. In 1914, the Tennessee Point Military Reservation adjacent to Fort Barry was acquired. In 1928, the Adjutant General of the U.S. Army announced that two batteries of coastal defense guns would be built, one on either side of the Golden Gate. The fortifications proposed for construction on this land were to augment those at the Presidio of San Francisco, in order to prevent the successful passage of hostile ships through the Golden Gate into the San Francisco Bay. In 1937, U.S. Congress approved the expenditure and the army acquired approximately 800 acres (324 ha) north of Rodeo Lagoon from the Marin Land and Cattle Company and designated the new reservation Fort Cronkhite in honor of Major General Adelbert Cronkhite who had commanded the 80th Division, National Army, during World War I. Fort Cronkhite was part of the 6th Air Defense Artillery Regiment,  Harbor Defense of San Francisco, headquartered at Fort Winfield Scott at the Presidio. In the fall of 1939, the U.S. Army consisted of only 200,000 enlisted soldiers and there was little need for new or updated housing. However, beginning in 1940, the military started drafting men into the army and navy, and military ranks began to swell as hundreds of thousands of draftees, all of whom had to be housed, entered the service. With the rapid military buildup of the military, tens of thousands of temporary wooden structures had to be built to house its growing ranks. The army’s Quartermaster Corps and the Corps of Engineers were put in charge of the building projects around the country. Using standard plans, all types of buildings could be built in a short time including barracks, mess halls, supply depots, chapels, and recreation buildings. Many of these wooden buildings were constructed at Fort Cronkhite and the first unit to move into the fort was Battery E of the 6th Air Defense Artillery in June 1941. Despite the rows of barracks at Fort Cronkhite, the 150 soldiers that manned Battery Townsley high above on Wolf Ridge had to live within the concrete walls of the gun bunker.

Battery Townsley was a casemated gun installation that mounted two 16-inch 50 caliber Mark II M1 Seacoast Rifles, each capable of shooting an armor-piercing projectile weighing 2,100 pounds (953 kg) a distance of 25 miles (40 km) out to sea. The guns and their associated ammunition magazines, power rooms, and crew quarters were covered by dozens of feet of concrete and earth to protect them from air and naval attack. This battery, named in honor of Major General Clarence P. Townsley, who served in World War I and a commandant at West Point Military Academy, was considered the ultimate military technology of that time and the result of careful long-term planning. As early as 1915, the army was eager to construct the 16-inch gun batteries at San Francisco, and by 1928, the decision had been made to install two batteries near the city, one on either side of the Golden Gate. In 1938, the army began construction of the high-security operation in the Marin Headlands. Civilians living in San Francisco knew that there were gun batteries nearby but their exact locations were not revealed. A battery of this design had never been actually fired before, so the soldiers underwent several months of practice before firing the guns for the first time. The men were subjected to endless training, often under difficult conditions, and were in a constant state of readiness. Despite the preparation, the guns were never fired at an enemy. In 1943, the invention of radar used to detect approaching ships and planes increased the effectiveness of the 16-inch guns and the nearby antiaircraft guns, but by the end of the war, the guns at Battery Townsley were made obsolete by long-range bombers, missiles, and the nuclear bomb. During the 1950s, Korean War soldiers were stationed at Fort Cronkhite and during the Cold War in the 1960s and early 1970s, the facility was used by soldiers operating the nearby Nike SF-88 missile site, one of the 300 across the nation. By 1974, the two Nike sites in the Marin Headlands had closed and the army began to deactivate the post. Fort Cronkhite is now part of the Golden Gate National Recreation Area, and in addition to providing office space for the National Park Service, the facility also supports many nonprofit, educational and environmental park partners. See a short video on Battery Townsley here. Read more here and here. Explore more of Fort Cronkhite and the Marin Headlands here: