Like the Western Star, which brought many tourists to Glacier Park in tour cars from other railroads, the NP used the Mainstreeter to bring tour cars to Livingston, where they would board buses to Yellowstone Park. By the mid-1960s, however, sleeping car passengers other than tours were growing thin: through the summer of 1964, the Mainstreeter carried only two Northern Pacific sleeping cars.
In 1964, after using Budd-built slumbercoaches for five years on the North Coast Limited, Northern Pacific bought eight more used slumbercoaches for the Mainstreeter. While welcomed by budget-minded passengers, the NP used one 40-bed slumbercoach to completely replace the two 22-bed Pullmans that had been running on the Mainstreeter. While slumbercoaches were inexpensive, they were also less comfortable than Pullmans, with significantly narrower beds.
Mail service was one of the revenue sources that kept trains like the Mainstreeter going, and the train often had six or more baggage cars to carry the mail. But the Post Office shifted to trucks and planes in the late 1960s, leaving the train with just one baggage car, a slumbercoach, buffet car, and two or three coaches.
By 1968, the NP had discontinued almost every train on its system, the main exceptions being the Mainstreeter, North Coast Limited, a Portland-Seattle train, and one or two locals served mainly by Budd Rail Diesel Cars. Most of those discontinued trains stayed within the boundaries of one state and so NP only needed to get permission from state rail authorities, not the ICC.
In 1968, Northern Pacific decided to discontinue the Mainstreeter. Since the Mainstreeter crossed state lines, NP had to apply for permission to the Interstate Commerce Commission (ICC). However, the ICC ordered to keep the train for at least another year, saying that the Mainstreeter stopped at 86 towns between Chicago and Seattle, only 26 of which were also served by the North Coast Limited. The ICC didn’t say why those particular towns deserved a rail connection when the many branch line trains that NP had already discontinued did not.
In any case, when NP applied to discontinue the train again in 1969, the ICC again rejected the application, complaining that the NP had deliberately tried to discourage ridership by, for example, making the Mainstreeter wait for freight trains. This led Railway Age to write about “The Strange Case of NP’s “Mainstreeter,” the Train the ICC Won’t Let Die.” The article noted that the train was clean and reliable but typically carried only around 40 passengers–not enough to fill a Greyhound bus.
In its decision, the ICC quoted NP President Robert McFarlane, who said in 1961: “I assure you that as long as the public use our trains, the North Coast Limited and Mainstreeter will continue just about as they are at present.” Although rail historians distinguish between McFarlane’s supposedly pro-passenger administration and the supposedly anti-passenger President Louis Menk, who took over in 1966, the reality is that the public largely abandoned the trains after 1962.
NP’s Mainstreeter had always been a step below the Western Star, but even the Star‘s patronage declined significantly. While the NP and, after the 1970 merger, Burlington Northern dutifully continued to run the Mainstreeter, when Amtrak took over in 1971 this train was one of the hundreds that the National Railroad Passenger Corporation (as Amtrak was originally called) decided wasn’t worth continuing.