Many major cities and regional population centers in the United States lack any form of inter-city passenger rail service, which would typically be provided by Amtrak. Six metropolitan statistical areas of more than one million residents do not have inter-city train service, nor do the states of South Dakota or Wyoming. There are no international passenger trains between the United States and Mexico, nor to Canada outside of Ontario, Montreal, and Vancouver.

Cities lacking inter-city rail service

For purposes of this list, a city is considered served if it is within 35 mi of an Amtrak or other inter-city passenger rail station. However, some of these cities may be served directly by Amtrak Thruway services. Unless otherwise noted, the provider of the last passenger service is noted in each of the following cities was Amtrak. A partial list of the cities with a greater metropolitan population of over 100,000 that are not served by some form of inter-city rail service is as follows (in order by decreasing population):

Cities with nearby services

In addition, the following cities are not directly served by inter-city rail service, but have a rail station within 35 mi of the city.

Cities with regional rail connections

The following cities are not directly served by inter-city rail service, but have regional or commuter rail service that connects to the inter-city rail network.

Other gaps

Amtrak provides no service to Mexico. From 1973 to 1981 Amtrak operated the Inter-American, which allowed for transfers between Laredo, Texas and Nuevo Laredo, Tamaulipas for connecting service with the Ferrocarriles Nacionales de México. The closest Amtrak service to Mexico may be found at stations along the western portion of the Sunset Limited and southwestern portion of the Texas Eagle in Texas, New Mexico, Arizona, and California; as well as the Pacific Surfliner service to Union Station in San Diego. Amtrak has studied rail lines formerly canceled that could renew service to some cities. Cities involved include Boise, Mobile, Tallahassee, the Quad Cities (four adjoining cities in northwest Illinois and southeastern Iowa), Billings, and Wichita. Proposals for high-speed rail could also restore service for several cities. Other services Amtrak could restore include the Pioneer (serving Chicago-Denver-Seattle via the California Zephyr), the Black Hawk (Chicago-Dubuque, eastern Iowa), the North Coast Hiawatha (serving Chicago-Fargo-Seattle via the Montana Rail Link), the Montrealer (Extension of the Vermonter from St. Albans, VT to Montreal, QC), the Coast Daylight (supplementing the Coast Starlight between Los Angeles and the Bay Area), and the New Orleans-Orlando segment of the Sunset Limited.