The YPG was first used by the military in 1942 for training desert troops. The mission changed in 1943, when the site began to be used as a testing ground for bridges and river crossing equipment, boats, vehicles and well drilling equipment under the designation of Yuma Test Branch, Army Corps of Engineers. In 1947, the Army began constructing new buildings and quarters at the Site but was later deactivated in 1950 because of the military austerity program. Since that time, the area of the original test site has been removed from YPG’s boundary. The Yuma Test Branch was reactivated in 1951 as the Yuma Test Station, focusing on desert and hot-weather research and for environmental and general purpose testing by the Army Technical Service and the Army Field Forces.

Between 1951 and 1963, the test station supported a variety of testing including Army Corps of Engineers Test Activities, Ordnance Test Activity, Quartermaster Corps and Airborne Test Activities, Chemical Test Activity, and Drone Test Activity.

By the late 1950s and early 1960s, the development of the “dual capability” Army (an army that could fight either a conventional or a nuclear war) and the passing of the Defense Act of 1958, and its resulting reorganization of the Defense Department, were significantly changing the mission of YPG. The Army sought to develop and provide weapons and equipment for a nuclear Army, such as efficiency and mobility (especially air transportability) of weaponry and instruments; enhanced battlefield mobility of ground and air vehicles; and significantly improved computer technology. These changes increased the workload of the Ordnance Test Activity and the available space for testing. In addition, the centralization of research, development, and supply in 1962 further complicated the organizational structure of the Yuma Test Station. In 1963, as a means to distinguish between the pre- and post-reorganization, the Yuma Test Station was renamed Yuma Proving Ground.

YPG submitted an application to the Arizona Department of Health Services (ADHS) for a Resource Conservation and Recovery Act (RCRA) permit in 1980 as a treatment, storage and disposal facility, with subsequent amendments in 1986 and 1988. Several Solid Waste Management Units (SWMUs) were operated under the permit. In 1996, ADEQ and YPG agreed on the management strategy for the SWMUs which involve investigation and cleanup under the Comprehensive Environmental Response Compensation and Liability Act (CERCLA). In 1997 the U.S. Environmental Protection Agency (EPA) conducted a RCRA facility assessment site inspection of the SWMUs at YPG and recommended response action for 51 SWMUs and six areas of concern, including 14 of the 19 SWMUs.

Between 1998 and 2002 the U.S. Army initiated a remedial investigation (RI) of YPG sites in 1998 as part of the DoD Installation Restoration Program (IRP) and identified 19 units for investigation under the RI/feasibility study (FS) CERCLA process. The sites were organized into four operable units based on their proximity to the main post at YPG and/or opportunities for rapid and similarity for cleanup. The RI report was finalized in July 2002.

The YPG did not qualify for placement in the National Priorities List, but regulatory oversight is provided by ADEQ under the IRP and Military Munitions Response Program (MMRP).