Re: South Fork Flathead River info?
Rich Osthoff's book Fly Fishing the Rocky Mountain Backcountry has a great chapter in it about the South Fork of the Flathead. He talks about the hike in sections as well as everything that can be floated. Sounds like an amazing river. If I lived anywhere close to the area, I know I'd be in there every summer. The chance to catch true native, wild trout sounds so tempting.
You can get the book on amazon for $12-15 and Kindle has it for $13.