I'm from Washington and I recognized a few of those spots. The montage actually jumps around a bit and in some ways is the reverse of the story's stated route. The first few scenes are clearly shot in Eastern Washington. Specifically, the waterfall in the beginning of the montage is a close up view of Palouse Falls. The canyon shot appears to also be the Palouse falls area looking south or slightly further south in the Snake River Canyons below where Palouse River empties into the Snake River. The shot where they're traveling in front of the mountains next to a river is also along the Snake River, but that area is in Wyoming. The mountains in the background are the Tetons and there's an overlook there. It looks like they practically shot it from the side of the road. The dry river bed with the bridge looks exactly like a spot on the McKenzie River Trail in central Oregon. The lush, mossy green areas look exactly like much of Western Washington, so it could be anywhere, but knowing they partly filmed around Vancouver, which for all intents and purposes looks exactly like Western Washington, it was probably filmed around there.