Chris, I might be interested. Would depend on my unpredictable work schedule, so I won't be able to say for a while.
Southern Yellowstone comes to mind for scenic value and good fishing. Start at the east side of Yellowstone Lake, end near Old Faithful. Lakes, rivers, thermal areas, etc.
The northern loop in Glacier NP is another option. Highline, Stoney Indian Pass, Ptarmigan Tunnel, then either Swiftcurrent of Peigan Passes. 60-70 miles, and lots of time above the trees.