Idaho Fish Report

The upper river is coming out of Island Park Reservoir at 345 CFS


by Mike Lawson
9-19-2025
208-558-7525
Website

The upper river is coming out of Island Park Reservoir at 345 CFS, with turbidity and algae still posing issues. It seems to be a day-to-day situation with people still finding nice fish in this area. Box Canyon provides good wading opportunities, with nymphing and dead drifting streamers, a great way to find fish. Most of the algae is on top of the water, so you want something that can get through that, though you may be able to find and target some rising fish. We are still hoping that the Ranch picks up in the coming days. We have been hearing word of some mahoganies showing up. We need cooler weather and perhaps rain to kick those fall-time hatches off. You can still head hunt on the ranch with rising fish spread out, but it will be some work. Still better than actual work!