Epic!
Although that word does not even begin to do justice...
I worked for a summer from Pocatello up the 15 through Idaho Falls then up the 20 through Ashton almost to the Targhee National Forest. The view from just about every turn in any road there is a calendar cover photo. Henry's Fork, The Fall, The Snake, etc.
Of course I was in my mid-20's at the time, and was hyper focused on trying to become a captain of industry, so I only fished once!
I've been back only once, when my wife and I spent 3 weeks on our honeymoon camping, hiking, and a little fishing through ID, MT and CO.
Man I really miss it up there!
Andy