YPG Heritage Center has exhibits on Yuma Proving Ground's WWII beginnings and mission through the years. Military testing in Yuma dates back to 1943, when the Army established the Yuma Test Branch along the Colorado River near Imperial Dam. Because engineers could control water flows, it was an ideal place to test portable bridges. About the same time, Camp Laguna was established as part of the California-Arizona Maneuver Area (CAMA), a vast area where more than a million soldiers trained for combat. After the war, Camp Laguna was deactivated, but Yuma Test Branch remained in limited operation until 1950, reopening as Yuma Test Station a year later. Renamed Yuma Proving Ground in 1963, this facility has helped to develop combat vehicles, aircraft and many weapons systems. One of the world’s largest military installations, YPG also is home to the Military Freefall School and GM’s hot-weather test track. Admission is free, and the museum is open Tuesday through Friday year round, call 328.3394 for hours or to arrange a group tour. Base entrance is limited to U.S. citizens except on escorted tours* and requires vehicle registration, insurance card and photo IDs. Take Highway 95 north to “big guns,” then turn left and watch for signs.