The Pacific Coast Theater of the American Civil War was the military operations in the United States on the Pacific Ocean and in the states and Territories west of the Continental Divide. The theater was encompassed by the Department of the Pacific that included the states of California, Oregon, and Nevada, the territories of Washington, Utah, and later Idaho. The operations of Union volunteer troop detachments, primarily from California, some from Oregon, and a few companies from Washington Territory, were directed mostly against Indians in the theater. Union and Confederate regular forces did not meet directly within the Pacific Department except in New Mexico Territory, however operations were directed against Confederate irregulars in California and strong garrisons were placed in Sout