FWIW, unless you're camping, I'd recommend staying outside the Park, in West Yellowstone or Gardener, rather than in the Park. West Yellowstone has a lot of lodging and dining options, Gardener, not so many. If you don't mind the long drives, Jackson and Cody are also options. I've never fished it, but the north fork of the Shoshone has always looked "trouty" to me, whenever I've driven to/from Cody out the eastern entrance of YNP.
Jeff
PS - The only places that I've stayed in the Park were the Lake Lodge, the share croppers' cabins at the Lake Lodge, and the Lodge at Grant Village. The Lake Lodge and cabins were expensive and very dated, such that I couldn't recommend them to anyone. The Lodge at Grant Village is much newer, but still a bit worn and expensive, sort of "Motel 6" accommodations at "Hilton" prices. Or so it seemed to me.
