In 1943, the organization that was to become Yuma Proving Ground (YPG) officially began operation under the designation of Yuma Test Branch. Its mission was to test bridges and river-crossing equipment, boats, vehicles, and well-drilling equipment. Part of the bridge testing activities consisted of strafing tests. During strafing tests, aircraft flew over and strafed various forms of bridges being tested. A practice minefield was also situated on a 640-acre tract of site. The types of ammunition and explosives known to be present include: practice mines, TNT, ammonium nitrate, dynamite and .30, .40 and .50 caliber small arms.

In the 1951, the Yuma Test Station was assigned the mission of research and development, engineering, and acceptance testing of artillery ammunition, small arms, recoilless rifles, mortars, grenades and mines. Engineering and acceptance testing also was performed on anti-aircraft weapons, ammunition and fuzes, with all live ammunition being fired at drone or towed targets. All forms of acceptance testing and firing were conducted from a specific firing line to specifically located impact area located on what is still the active YPG Installation. Facilities, including a toxic chemical laboratory, chemical storage area, and chemical warfare range were built at YPG for environmental and surveillance tests of chemical agents and protective equipment. No records of actual storage or use of CWM was found for the time period of the Yuma Test Station.

From 1955 to 1983, Approximately 5,248 acres were declared excess and disposed of with a majority of the land being transferred to the Bureau of Reclamation and in October of 1994 Four CAIS (mustard) were found at Yuma Proving Ground.

This UXOInfo.com UXO Site Inventory database entry is for the potential or suspect RCWM areas within Yuma Proving Ground. The entry does not include the Operational Range Area or any MMRP site within Yum Proving Grounds which are separate entries within the database.

There are three RCWM sites associated with Yuma Proving Grounds including the Chemical Agent Disposal Area, the Chemical Storage Area, and The West Environmental Test Area.