Montana Rail Link’s former Northern Pacific route over Mullan Pass west of Helena, Montana, features a series of amazing curves to climb the eastern grade of the pass. In the foreground, a westbound BNSF freight has come to a stop at the yellow approach signal at the west end of Austin siding and is staying short of Mullan Pass Road grade crossing, waiting for a meet with an eastbound. Above the cab of No. 4730, the eastbound freight approaches the west signal for Austin siding, while the rear of the train can still be seen above left entering Iron Ridge cut. Amazing engineering to keep the grade at 2.2 percent!