At the 9,401 ft. siding at Garrison (MP 50.9), the former line over Homestake Pass turns away the south; this longer remnant reaches through Deer Lodge to the junction with the UP at Silver Bow, and reaches to the mining town of Butte just on the west side of Homestake Pass. The former Milwaukee Road line over Pipestone Pass also ran this way, paralleling the former NP line all the way to Butte. The Mullan Pass line continues just north of due east, to climb the west slope of the pass, single track CTC, speed limit 45 mph, on the climb to the Continental Divide at Mullan Pass, turning north past Bradley (MP 43.5), where the speed limit is 35 mph for the curves to come, east-northeast, just west of due north, northeast and then east, past the 6,213 ft. siding at Avon (MP 37.7), where the speed limit is back to 45 mph, east-southeast past Gilbert, a detector at MP 33.0, where the speed limit has reached the line's maximum 60 mph, and the 8,786 ft. siding at Elliston, northeast, north-northeast, past the departure of the erstwhile original right-of-way on the east side, and east-northeast past the former location of a wye on the north side with an erstwhile logging spur, to the 7,650 ft. siding at Blossburg (MP 20.5), where the speed limit has dropped to 45 mph again.
The Continental Divide, 5,548 ft. elevation (20 ft. lower than Bozeman Pass, further east) is just at the west end of the 3,898 ft. long Blossburg Tunnel (MP 19.6), which passes beneath the erstwhile original r-o-w, and turns north beyond the east portal of the tunnel, descending the east side of Mullan Pass, with speed limit 25 mph past spectacular curved trestles in side valleys on the north side of the main valley— first Skyline Trestle over Austin Gulch—just west of where the erstwhile original r-o-w trails in on the north side as the line turns east, past signals at Skyline (MP 18.6), turning north again to Greenhorn Trestle over the eponymous gulch, where it makes a clockwise horseshoe back to the south, turning east, south, and east-northeast past signals at Weed (MP 15.8), a bypass of the erstwhile Iron Ridge Tunnel, north of the present line, a clockwise horseshoe back to the west-southwest, on the other side of a deep gulch, a turn southwest, a counter-clockwise horseshoe around a bluff, back to the east, the 6,825 ft. siding at Austin (MP 12.9), and east-northeast to Clough Junction, where a branch from Marysville once turned away the north and the line turns east, past Birdseye (MP 7.7), where the speed limit has risen to 35 mph, and then southeast.
The line is Two Main Tracks, CTC, from Tobin (MP 5.1), where the speed limit has risen to 45 mph, past a spur at Fort Harrison (MP 4.2) and Helena Junction (MP 3.0), a BNSF (ex-GN) line from Great Falls trails in from the north, an erstwhile branch from Rimini once trailed in from the south, and the line turns just south of due east to Helena (MP 0.0), where 2MT end in Yard Limits, with speed restriction 10 mph, the station platform and depot are on the south side of the line, and the former GN r-o-w once ran parallel on the south side of the line.