Experience heavy-duty action on the rough and tough Mullan Pass where up to three sets of helpers are needed to haul big tonnage up 2.2 percent grades. Ride around horseshoe curves, over two long trestles and through the 3,896-foot tunnel crossing the Continental Divide. Marvel at the endless vistas of Montana's Big Sky country. Share the excitement on this legendary pass in 1990 when Burlington Northern and Montana Rail shared the line. See coal trains grind their way past Iron Ridge and watch huge clouds of diesel exhaust roll out of the tunnel. Take a ride across the Pass in a lead helper engine. You can't get enough of this awesome experience!