West Montana suggestions

We looked at the West Glacier KOA but aren't a fan of camping without trees.

Agreed. The West Glacier KOA is a very nice CG, and tours of Glacier NP pick you up right at the CG (they don't do that for any of the other CGs outside the park, that I know of). But when we had made our reservations for it, we were looking at old pictures and were looking forward to camping in a pine woods. Got there - almost no trees! Turned out they had cut many of them down to make room for bigger rigs and those who want satellite connections. :( We enjoyed our stay, but would sure have loved the woods. I believe it was Mountain Meadows we drove into & peeked at, and they are quite wooded.