Camp Mabry (ICAO: KATT) is a military installation in Austin, Texas that houses the headquarters of the Texas Military Forces. Its original 90-acre (360,000 m2) site, three miles (5 km) northwest of downtown west of Mopac Expressway, was deeded from the city to the state in 1892. It was named for Brigadier General Woodford H. Mabry the Adjutant General of Texas from January 23, 1891 to May 4, 1898. The camp was added to the National Register of Historic Places in 1996.
Camp Mabry is the third-oldest active military installation in Texas behind Fort Sam Houston and Fort Bliss. Camp Mabry currently houses the office of the Adjutant General, as well as the headquarters of the Texas Army National Guard, the Texas Air National Guard, and the Texas State Guard. Other facilities include the 136th Regional Training Institute, state Combined Support Maintenance Shops, the armory of the 36th Infantry Division headquarters, a clinic, a parachute packing and storage facility, and additional storage buildings. In 1992 the Texas Military Forces Museum opened on the site.
For many years at the turn of the 20th century, the camp was home to annual encampments by the Texas state militia, who hosted reenactments and demonstrations for the people of Austin. Grandstands were built on the site, and further improvements to the site were funded by paid admissions to the events. By 1911, the camp had expanded to more than 385 acres (1.56 km2). The first permanent building onsite, an arsenal, was completed in 1915 and allowed military weaponry and equipment to be moved out of storage in the capitol building.