The Umatilla Chemical Depot opened in 1941, to prepare for World War II. The depot's mission was to store and maintain a variety of military items, from blankets to ammunition. The depot took on its chemical weapons storage mission in 1962. From 1990 to 1994 the facility reorganized in preparation for eventual closure, shipping all conventional ammunition and supplies to other installations. On October 25, 2011, the last barrel of HD mustard agent was destroyed and there is no longer a risk of chemical accident in Oregon and Washington.