An eastbound BNSF stack train prepares for a meet with a westbound ethanol train at Bison on a smoky Saturday morning.

A westbound BNSF ethanol train works its way up the east slope of Marias Pass near Bison

The eastbound train 8 (Empire Builder) heads towards Bison on a nice clear day in Montana.

A colorful consist powers a westbound Burlington Northern Santa Fe grain train at Bison, Montana, on March 2, 1997. The train is powered by an eclectic set of motive power comprised of BNSF GE C44... (more)

An eastbound Burlington Northern Santa Fe intermodal train passes a small mountain lake on the border of Glacier National Park while crossing Marias Pass west of Bison, Montana, on June 4, 2002.

In a falling snow on the southern border of Glacier National Park, an eastbound Burlington Northern grain empty led by LMX GE B39-8 No. 8536 has just summited Marias Pass and approaches Bison, Mon... (more)

A heavily powered eastbound manifest takes its time moving downhill at Bison, Montana. The mountains in the scene are actually in the southern part of Glacier National Park.

An eastbound stack train pulls out onto the high plains of Montana after coming down off Marias Pass. The altitude here is about 5000 feet.

A short but steep climb up a rocky ridge reveals a nice vantage point to catch this eastbounder at Bison siding. The mountain in the background is Calf Robe Mountain (8000 feet altitude).

This high priority eastbounder has just passed the Marias Pass summit and is rolling downhill with the dynamic brakes beginning to howl.

The jagged mountains of Glacier National Park fill the background behind an eastbound Burlington Northern Santa Fe stack train at Bison, Montana, on the morning of June 4, 2002.

Snow dusts the mountains of Glacier National Park on Marias Pass on the autumn day of October 8, 2018, as a westbound BNSF grain train approaches Bison, Montana.

Eastbound mixed freight.

Surrounded by a winter wonderland on the southern border of Glacier National Park, Amtrak’s eastbound Empire Builder has just summited Marias Pass and approaches Bison, Montana, on a snowy March 3... (more)

It can’t decide it whether it’s winter or fall as snow mixes with bright yellow trees on Marias Pass as a westbound BNSF grain train approaches the east switch at Bison, Montana, on October 8, 201... (more)