Building Site

The site of Building 640 in the Presidio of San Francisco

Building No. 640, built in 1921 as an air mail carrier hanger for the Air Postal Service, was converted by the US Army as the first Military Intelligence Service (MIS) language school to secretly train and house 60 linguist soldiers as students (58 Japanese American and two Caucasians) one month before the attack on Pearl Harbor. It still stands at West Crissy Field east of the old Commissary Building Sports Basement in the Presidio of San Francisco. Its location is on a two-acre site along Mason Street and across the West Crissy Field Green. The site captures breathtaking views of powerful icons, the Golden Gate, Angel Island and Alcatraz.

Building 640 is recognized as the birthplace of the Military Intelligence Service Language School, forerunner of the renowned Defense Language Institute of Monterey. The Presidio of San Francisco is one of the newer National Parks and has National Landmark status.
Explore on-site photos showing the reconstruction of Building 640 for the MIS Historic Learning Center.

640 Mason Street, Crissy Field West, Presidio of San Francisco, CA. 94129