Island Park Reservoir is the impoundment on the Henrys Fork that feeds the famous river below it, a broad, fertile, weed-rich stillwater up in the Island Park caldera holding rainbows and a few big browns. It's a boat-and-tube fishery, played with leeches, damsels, and chironomids over the weed beds and along the dam face. The fishing swings with the reservoir level and the irrigation draw, and it can get warm and weedy by late summer. Spring and fall, with the caldera rim all around and the big fish on the move, it's a fine, underrated stillwater.
- Reservoir
- Mixed