What follows are the dates locomotives were last dispatched out of Chama (mostly east to Alamosa). While the locomotives may have been used around Alamosa after they left Chama, the offical retirement date probably is fairly close to what follows:
480 - 5/31/64
481 - 3/28/61 (overhauled in 1966 but never run)
482 - 4/20/59
483 - 12/6/68 (last DRGW engine to leave Chama)
484 - 8/25/68 (helper on last revenue freight)
485 - 1954 (don't know when it fell in the pit)
486 - 11/3/61
487 - 10/27/67
488 - 11/30/66
489 - 5/13/61
490 - 1959? (when 497-98 got wrecked in 1/60, 497 got its tender).
491 - 4/19/63
492 - 8/26/66
493 - 7/18/68
494 - 8/3/62
495 - 1/18/61
496 - 1954? (I hear it sat a while before it got cut up )
497 - 12/3?/67 (went to Durango and never came back)
498 - 8/29/68 (road engine on last revenue freight)
499 - 12/4/63
If anyone has more info, please post it.