The Sierra Army Depot (SIAD) was established in 1942, answering a need for an excellent, defensible munitions depot. The northern California area was deemed the perfect place for a depot because it was remote, bordered by major rail lines, had the perfect climate for ammunition storage, was far enough away from the coast to be secure from Japanese attacks (this was World War II, after all), and near enough to military posts for the shipment of supplies.


After the war, the depot's mission extended to cover the dismantling and renovation of ammunition, and for a brief time in the 1980s, it was the storage site housing unarmed nuclear weapons. After years of operation, the depot became the Army's Center of Technical Excellence for Operational Project Stocks, housing the repair facilities and supplies for the Inland Petroleum Distribution System and the Water Support System. Located in a desert plain, the SIAD has the biggest open burn/open detonation capabilities in the U.S. As a result, the depot houses fourteen pits that can detonate up to 10,000 pounds of explosives per pit. However as of 2001, the SIAD decided to incorporate recycling-based solutions rather than use the open burning/open detonation process.


As a result of the BRAC of 1995, the depot's ammunition mission was reduced. Shortly after, in 2002, it joined the Ground Systems Industrial Enterprise (GSIE). GSIE is a corporate umbrella organization for six Army installations: the Sierra Army Depot, the Rock Island Arsenal, the Watervliet Arsenal, the Lima Army Tank Plant, the Anniston Army Depot, and the Red River Army Depot.