Moonrise over Alco: Sunset on December 17, 1964, finds Santa Fe 600/2140/2116/2124 setting out from La Junta, Colorado with the overnight freight for Albuquerque. At Raton, the lead units will be cut off, RSD7 600 for service up the branch to the Koehler coal mine, and RSD5 2140 for helper service over Raton. The 600 is one of a pair of former Alco 2250-hp RSD7 demonstrators, DL600 and DL601. Customers were less than enthusiastic and Alco up-rated subsequent units to 2400-hp. Santa Fe bought ten.