Call Idaho River Sports in Boise, ID.
1521 N. 13th
Boise, ID 83702
They can send you Grant Amaral's river guide book:
"Idaho-The Whitewater State, A guide book".
It's the best for ID.
The folks at the shop can give you ph #'s to Jackson Hole's river shop. They'd have the best selection of river guides, I bet.
For MT try: www.whitewatermaps.com
I got a Gallatin map at Northern Lights Trading Co. in Bozeman. There was not a MT guide book at that time.
Just get in the car & drive. The scenery can't be beat.
Watch out for logs. Enjoy the hot springs. btw- I hear the snow pack was low this year. No problem, the rivers are deep & fun at moderate to low flows.
Paddle for Life.