A D&RGW A-B-B F-unit combination on the eastbound Rio Grand Zephyr gets an assist from leading GP40-2 3107. The train is being serviced at the classic depot in Grand Junction, Colorado, in August 1976, during the period when the Rio Grande — which declined to join Amtrak — was required to continue its own passenger service. Unit 3107 was built in 1972 as the Rio Grande's class EF430D-6; in 2000 it became Union Pacific 5261 and was renumbered 1361 in 2002.