The Air Force has begun construction of a new underground nuclear weapons storage and handling facility at F.E. Warren Air Force Base in Cheyenne, Wyoming. The new Weapons Storage and Maintenance Facility (WSMF; sometimes called Weapons Generation Facility), which will replace the current Weapons Storage Area (WSA), will be a 90,000-square-foot reinforced concrete and earth-covered facility with supporting surface structures. – Federation of American Scientists