United States. Army. Western Defense Command

On 4 June 1942, the U.S. Army, Western Theater of Operations, was authorized to create a War Disaster Relief Plan for Montana, Idaho, Washington, Oregon, California, Nevada, Utah, and Arizona. The War Disaster Relief Plan was "to provide the course of action to be taken by the Army in case of a total or partial failure of civilian and other governmental agencies to perform their respective War Disaster Relief functions," in the case of enemy invasion or sporadic raids including bombing raids. To achieve this goal, the Western Defense Command (4th U.S. Army) and the Ninth Service Command divided the Western Theater of Operations into four War Disaster Relief Administrative Areas. Each Administrative Area was responsible for writing War Disaster Relief Plans specific to their area of responsibility, to be completed by 1 November 1942. The Northern Administrative Area encompassed Oregon, Washington, Idaho, and Montana. Utah, Northern Nevada, and Northern California were under the Central Administrative Area. Southern California, Southern Nevada and Arizona were under the Southern Administrative Area. The Southern Land Frontier Sector Administrative Area was responsible for the region bordering Mexico.