Heading for The Pass (Infrared) ©2018 James D Peterson. On a late summer afternoon, Engine 489 hauls its passengers through the southern San Juan Mountains on its way from Antonito, Colorado to Chama, New Mexico. This excursion was accompanied by some late summer monsoon activity along the route of the historic Cumbres and Toltec Scenic Railroad, formerly part of the Denver and Rio Grande Western Railroad.