On June 1, 1942, the Bureau of Reclamation transferred of the Heart Mountain Irrigation Project and several CCC buildings to the War Relocation Authority, the branch of the Western Defense Command responsible for administration of the incarceration program. More than 2,000 laborers, including men employed by the Harza Engineering Company of Chicago and the Hamilton Bridge Company of Kansas City, began work on June 8, under the direction of the Army Corps of Engineers. The workers enclosed of arid buffalo grass and sagebrush with a high barbed wire fence and nine guard towers. Within this perimeter, 650 military-style barracks were laid out in a street grid, with administrative, hospital, educational, and utility facilities, and 468 residential dormitories to house the internees.