Specifications 2031-87 (with omissions). 2055. 66 two-bedroom and 27 three-bedroom prefabricated, precut or sectionalized residences for Government camps at Cannonball Dam, Cannonball River unit, N. Dak., Shadehill Dam, Grand River unit, S. Dak., Bixby Dam, Moreau River unit, S. Dak., Keyhole Dam. Belle Fourche unit. Wyo., Powder River unit, Mont.. Missouri Basin project.