Which is on the Montana-Idaho border way up in the mountains in a very sparsely-populated area. It's operated by the Lookout Pass Ski Area and one end of the trail is the ski lodge. Going on that trail is truly memorable:
> The Route of the Hiawatha mountain bike or hike trail is 15 miles long with 10 train tunnels and 7 sky-high trestles. The ride starts with a trip through the 1.661 mile long St. Paul Pass Tunnel, also known as the Taft Tunnel. It is a highlight of the trail that follows the crest of the Bitterroot Mountains near Lookout Pass Ski Area. The best part is.... it's mostly downhill with shuttle buses available to transport you and your bike back to the top.
Nice, that's a part of the old Milwaukee Road from Chicago to Seattle! In photos from your link, you can that some of the structures for holding the overhead catenary wire are still present. When that line was built, that section was the longest electrified train line in the world. I'm pretty sure they did it because of the grades.
I just rode the Hiawatha this summer! Really touristy, but lots of fun and so scenic. I would have guessed that more of the Trail of the Coeur D'Alenes would have been used as opposed to the Hiawatha. Or perhaps my geography is failing me, but I think you have to go a bit north off the Cd'A to get to Hiawatha.
https://gis.railstotrails.org/grtamerican/
It includes the Route of the Hiawatha:
https://www.ridethehiawatha.com/the-trail
Which is on the Montana-Idaho border way up in the mountains in a very sparsely-populated area. It's operated by the Lookout Pass Ski Area and one end of the trail is the ski lodge. Going on that trail is truly memorable:
> The Route of the Hiawatha mountain bike or hike trail is 15 miles long with 10 train tunnels and 7 sky-high trestles. The ride starts with a trip through the 1.661 mile long St. Paul Pass Tunnel, also known as the Taft Tunnel. It is a highlight of the trail that follows the crest of the Bitterroot Mountains near Lookout Pass Ski Area. The best part is.... it's mostly downhill with shuttle buses available to transport you and your bike back to the top.
https://www.traillink.com/trail/route-of-the-hiawatha/