The camp continued service as a military installation by being utilized as an amphibious training center. Training with heavy artillery. The amphibious warfare instructors at Callan trained combat teams from divisions stationed at San Luis Obispo and Camp Cooke, California. The War Department declared Camp Callan surplus to the needs of the government in November 1945. Looking into the business end of a coastal artillery gun, early 1941.
Artillerymen learn the art of camouflage.
Coast artillery and antiaircraft training were the major emphasis at Camp Callan. In addition to these areas, Camp Callan had numerous structures such as ammunition magazines, an ordnance warehouse, and an ordnance machine shop. The April 1941 vicinity map shows four large magazines and three smaller magazines in the ordnance storage area. Artillerymen undergoing infantry training. Camp Callan also had a chemical section assigned to the base and elements of the 77th Smoke Generator Company.