Carryall, an infrastructure proposal under Project Plowshare, began in 1963 while the California Department of Highways (today's Caltrans) was in the early stages of constructing the western end of Interstate 40. Its goal was to sidestep the scenic but slow Route 66, a road that didn't fit into the national defense-supporting highway network advocated by President Eisenhower. A feasibility study conducted by the Atchison, Topeka and Santa Fe Railway—or ATSF—asked the U.S. Atomic Energy Commission for help to build a shortcut through the Bristol Mountains.