History

The train was a remnant of the original California Zephyr, which was jointly operated by the Chicago, Burlington and Quincy Railroad, Denver and Rio Grande Western Railroad and Western Pacific Railroad. This iteration of the Zephyr ended operations on March 22, 1970, when the Western Pacific discontinued its portion.

The Rio Grande Zephyr commenced operation using the D&RGW's portion of the California Zephyr route from Denver, Colorado to Salt Lake City, Utah. The route was extended to Ogden, Utah to allow for California bound passengers to connect to the City of San Francisco and later the San Francisco Zephyr, which did not serve Salt Lake. The Rio Grande Zephyr used mostly the same equipment and staff as was formerly used for the California Zephyr. Since the train was no longer an overnight affair, sleeping cars and a full baggage car were not required. The D&RGW sold their sleepers to the Ferrocarriles Nacionales de México, while their one baggage car was sold to the Algoma Central Railway in Canada.

Amtrak planned to take over service of the original California Zephyr on May 1, 1971. However the Rio Grande and Amtrak could not come to terms over a contract agreement, and just four days before Amtrak began operation, Union Pacific's Overland Route was substituted for the Rio Grande's Moffat Tunnel Route. The Amtrak service was initially named the San Francisco Zephyr, as the route combined portions of the routes of the former California Zephyr and the City of San Francisco trains.

For twelve years the Rio Grande Zephyr operated three days a week in each direction. It never operated on Wednesday. In 1983 the D&RGW reversed its earlier opposition and elected to join Amtrak, citing increasing losses in passenger operations. Amtrak re-routed the San Francisco Zephyr over the D&RGW's main line between Denver and Salt Lake City, Utah, which was its original preference in 1971. The change was initially scheduled for April 25, but a mudslide at Thistle, Utah closed the D&RGW's main line and delayed the change until July 16. While the Utah portion of the line was closed, The Rio Grande Zephyr continued to operate on a truncated route between Denver and Grand Junction, Colorado until the train was discontinued on April 24, 1983. After the D&RGW tracks were re-opened, Amtrak brought back the California Zephyr name.