What is your timeframe? If your headed out before July 15th...I'd probably stay around the Madison Junction, or West Yellowstone and focus on the Upper & Lower Madison outside the park, and the Madison & Firehole inside the park...After July 15th, I'd be more inclined to fish the Yellowstone around Livingston. In the park, I'd fish the Yellowstone in the Canyon, Slough, & Soda Butte. Dont waste your time with the Y. Stone below the lake...there arent many Cuttthroat left to catch. There is some great fishing around Jackson Hole and Cody too. Cheers.