Marias Pass Loop

Was doing some research about the Marias Pass and found this loop interesting. I assume that it must be used for helper engines to head back down the pass?

It is used for turning snowplows and flangers, helper locomotives don't need to be turned.

It's know as a balloon track.

And clearly it replaced an earlier wye, which likely was built to turn steam helpers (as well as snowplows etc.).

Modeling that for the original Microsoft Train Simulator broke the simulator. The game engine couldn't comprehend projecting a path that came back across the same point it had come from...

That's why it wasn't included.

The track is no longer in service and switch has been removed. Instead, the wye has been rebuilt at Glacier Park (East Glacier).