Railroads have been an important method of transportation in Montana since the 1880s. Historically, the state was traversed by the main lines of three east-west transcontinental routes: the Milwaukee Road, the Great Northern, and the Northern Pacific. Today, the BNSF Railway is the state's largest railroad, its main transcontinental route incorporating the former Great Northern main line across the state. Montana RailLink, a privately held Class II railroad, operates former Northern Pacific trackage in western Montana.

What is the states largest railway?