Dropouts are different.

If it's a Glacier N.P. rental, it could be from Backroads (see embedded video at the right in the link.
Here's another link to a page about their bikes. According to another thread, they sold off some of their fleet about 10 years ago (and may have done so again since). If it is a Backroads bike, it could be an Airborne frame.

I have a Sampson Kalispell from 1995- Still my main road bike- looks a lot like that. It's also bead blasted titanium and it has always looked exactly the same.

Thanks for all of the replies, but the bike was sold. Guess this will remain a mystery.