The airfield which would become Castle Air Force Base in Atwater, California, was opened on September 29, 1941 as the Army Air Corps Basic Flying School. Its mission was as a pilot and aircrew training facility operated by the United States Army Air Force. In 1943 it was renamed Merced Army Airfield and kept that name until it was taken over by the Strategic Air Command (SAC).
The former Castle Air Force Base, like numerous military installations across the country, was contaminated by fuels, oils, solvents, cleaners and paints used to operate and maintain aircraft for national defense. Federal laws such as the Comprehensive Environmental Response, Compensation and Liability Act, require the Air Force, overseen by state and federal regulators, to clean up this soil and groundwater pollution, a task which is almost finished. Read more about cleanup activities here.
Most of the property was transferred to the County of Merced, the Local Redevelopment Authority for Castle. The federal government received 649 acres for a federal penitentiary and another 186 acres was sold.
The airport, home to one of the longest runways in the western United States at 11,802 feet, is open 24/7 for general aviation purposes. The county operates the airport as Castle Airport, Aviation Development Center.
A total of 1,834 people work at 42 businesses and institutions on the former base.
The United States Penitentiary, Atwater is barely visible in the distance from the raised vantage point afforded by one of the former landfills. This high security facility houses about 1,402 male inmates. An adjacent, minimum security satellite facility, known as Atwater Camp, houses 135 male prisoners. The penitentiary and camp provide about 350 federal jobs in security, healthcare, and education, among other categories.