I was there two years ago. Glacier NP is awesome and there is some great riding nearby. I did two separate rides on the Whitefish trails,
https://www.mtbproject.com/trail/565...eaver-lollipop. I also spent a day in the bike park at Whitefish Mountain. I found the bike park to be much more downhill oriented than some I've visited, still fun, but not much to ride in the intermediate range, one beginner trail and several more advanced. In addition, there is actually a trail in Glacier Park that allows bikes:
Old Flathead Ranger Station Trail Glacier National Park. This is an old double-track that has turned into singletrack and is novel for the fact that it allows mountain bikes in a national park! The views are scenic and the terrain is interesting.
I was intrigued by this place:
Whitefish Bike Retreat - Whitefish Bike Retreat. I drove in and wanted to stay there, but they were full up during my visit. Have fun, watch for bears and other wildlife.