| Union Pacific Railroad 4-6-6-4 Challenger Class CSA-1 3803 at North Platte, Nebraska on September 15, 1957, Kodachrome by Dick Rumbolz, Chuck Zeiler collection. Number 3803 was built by Alco in September 1936 as UP 3903 (c/n 68748), converted to burn oil and renumbered to 3803 in April 1944, retired May 1959. Cabside Class: CSA-69 |