When the North Coast Limited got a faster schedule in November 1952 the Mainstreeter was introduced, running roughly on the North Coast's old schedule but via Helena.

Unlike the North Coast the Mainstreeter was not a true streamliner as it carried both new lightweight and traditional heavyweight coaches.

The name referred to the Northern Pacific's slogan, "Main Street of the Northwest."

While Amtrak did not retain the train as part of its initial route structure, it created a new train named the North Coast Hiawatha several months afterwards.

Unlike many other trains the Mainstreeter did not have specific sets of equipment built for it.