I just went out to Mt. Baker yesterday, and I have some more thoughts!
I think Leah intended to spend some time in Bellingham, at least overnight. As far as we know, it's the only place where she spent any significant amount of time-- at least a movie and a meal.
The drive out to Mt. Maker is pretty much a straight shot east. Once you're out of Bellingham, it very quickly turns into farmland and then forest. The towns between Bellingham and Mt. Baker are tiny and primarily residential-- again, farms and forest. The town of Glacier is the last stop before getting to the mountain, and there are small shops and restaurants where people can stock up before going up to the mountain.
Something that stuck out to me is that Canyon Creek Road, the road where Leah's car was found, is easy to miss. Leah definitely did not accidentally turn onto it, assuming that she was alive and driving her car out towards Baker. Her car was *intentionally* dumped there because it is off of the main road and not a place where someone would be easily spotted. Canyon Creek Road is also easier to spot on the way *back* from Baker, which makes me think that it's possible Leah actually did make it past Glacier.
There IS, however, a campsite very close to Canyon Creek Road called Douglas Fir Campground. It would have been closed in March, so I don't think Leah would have been able to camp there (again, assuming she was alive and made it out of Bellingham). However, given that it would have been empty, it may have been a convenient place to bury a body. It might not be the smartest idea to dispose of a body so close to where the car was dumped, but it's possible. Were any of the nearby campgrounds ever searched with dogs?
Yet another rough theory I had was that Leah could have been abducted from Glacier. There is one public restroom at the far end of a parking lot for a convenience store (Graham's). Again, Glacier is the last place to stock up on supplies and use a restroom before heading up Mt. Baker. Given how isolated the restroom is, it would be *very* easy to surprise someone, and there is even a small trail right behind the building. Was anyone in Glacier or anyone form Graham's ever questioned about whether they saw Leah?
Lastly, if Leah *was* planning to do any sort of winter hiking/camping, she would have needed a Northwest Forest Pass and appropriate supplies. Was she ever at the REI in Bellingham or at the ranger station in Glacier to get a pass? If not, if she did make it out there to do some adventuring, she would have needed to be with someone who *did* have a pass. Anyone know a guy named Barry who had a Northwest Forest Pass?
These are all half-formed ideas, but actually being out in the area really helped me get a better idea of the situation. Regardless, if Leah did plan to head out to Mt. Baker, it was a terrible time of year for a novice to do any sort of trekking.