Scarecrow, if I'm going to the park to fish I'd hit yellowstone lake and rent a boat or take a guided trip, pretty reasonable. HUGE lake trout to be had. All you need it seems is some silver spoons I've heard. Did a job down there last year, never had time to fish but the guy running the job was staying there and went down and hit the lake every night in his kayak and slayed 'em. Some are very large and the park service wants them gone. We looked into boat rentals and they seemed fairly reasonable... Just a thought, not trying to divert you from your original plan, I'm sure fly fishing would be fun in the park, just be on the lookout for grizzlies at all times.