It’s one of the roughest, toughest mountain passes, where heavy tonnage trains battle 2.2 percent grades and up to three sets of helpers are needed for the haul. It’s a line of repeated horseshoe curves, with two long trestles, and a 3,896-foot long tunnel that crosses the Continental Divide. It’s located in the Big Sky country of Montana, where endless vistas of mountains and cloud-filled skies create a scenic backdrop for trains of 100-plus cars. It’s a place where two railroads juggle nonstop traffic over 29 miles of partially single-tracked mountain rails. In short: Welcome to Mullan Pass! Burlington Northern and Montana Rail Link shared the line when Video Rails captured the excitement on this legendary Pass in 1990. Starting at Helena Junction, we see BN and MRL trains depart for the steep climb to the summit. Every westbound train needs helpers and MRL’s heaviest power is assigned to its helper pool. SD40-2s and SD45s make up the bulk of the power seen here. 15,000-ton coal trains with 45,000 HP grind their way up the 2.2 percent grade, past Iron Ridge, Greenhorn Trestle, and Skyline Trestle to Mullan Tunnel, Blossburg Siding, and Elliston. Huge clouds of diesel exhaust billow out of the tunnel, making it easy to see why it’s called the “Black Fog of Blossburg.”
A special treat is a cab ride across the Pass in the lead helper engine of BN Train 195, a daily mixed freight. Whether you’re viewing the line from the crews’ perspective, from trackside, or through vast panorama views, railroading on Mullan Pass is an awesome experience you’ll want to enjoy again and again!