The Pioneer was an Amtrak long-distance passenger train that ran between Seattle and Chicago via Portland, Boise, Salt Lake City, and Denver.

When the Denver and Rio Grande Western Railroad decided to join Amtrak in 1983, Amtrak renamed the San Francisco Zephyr to California Zephyr, shifted it south to the Moffat Tunnel Route, and changed its interchange point with the Pioneer from Ogden to Salt Lake City, the Pioneer's terminus.

[9] While visiting Pendleton, Oregon on February 22, Amtrak President Thomas M. Downs said the Pioneer could be converted to a coach-only Chicago–Portland mail-and-express train operating on an all-Union Pacific routing through Iowa and Wyoming (but missing Ogden) if interested states could provide about $4.8 million to fund the existing operation through that October when the new train could start.

Oregon refused to provide the loan guarantees because it found Amtrak's collateral (ex-Santa Fe Hi-Level cars) unacceptable.

With the start of through service with the San Francisco Zephyr in 1981 the Pioneer received bi-level Superliner coaches, but the single-level sleeping car and lounge remained until 1982, when the train went all-Superliner.

[1] In accordance with the Passenger Rail Investment and Improvement Act of 2008 Amtrak evaluated the possibility of restoring service to the Pioneer and other discontinued long-distance routes.

Amtrak projected lower ridership than in the mid-1990s owing to the proliferation of low-cost air travel between Seattle and Salt Lake City (particularly Southwest Airlines)[17] In 2020, local rail advocates started an informal Greater Northwest Passenger Rail Working Group focused on restarting the Pioneer, North Coast Hiawatha, and other routes in the Northwestern United States.

The group calls on Congress to give it official status, create an interstate passenger rail commission, and allocate a percentage of new train funding to rural long-distance routes.

This approach is modeled on the Gulf Coast Working Group and Southern Rail Commission, which are on track to restore Amtrak service between New Orleans and Mobile in 2022.

[18][19] On June 8, 2021, the Boise City Council passed a resolution in support of restoring the Pioneer, using similar language to the working group's.

[30] In 2022, the IIJA enabled the Federal Railroad Administration to launch the Corridor ID Program, a system to develop new passenger rail services.