The Train of Tomorrow was an American demonstrator train built as a collaboration between General Motors (GM) and Pullman-Standard between 1945 and 1947. It was the first new train to consist entirely of dome cars, which were the brainchild of GM vice president and Electro-Motive Division (EMD) general manager Cyrus Osborn, who conceived the idea while riding in either an F-unit or a caboose in the Rocky Mountains in Glenwood Canyon, Colorado. After GM built a 45-foot (14 m) scale model of the train for $101,772 ($1,414,214 in 2021 dollars) and displayed it to 350 officials from 55 different Class I railroads in 1945, the Train of Tomorrow was built by Pullman-Standard between October 1946 and May 1947.