The outflow from Island Park Dam has cleared resulting in much better fishing in the river below down to Riverside Campground. The reason for this rather sudden clear-up seems obscure, but a good analysis for its presence and of the previous suspended residue within can be seen on the 7/22/16 Henry’s Fork Anglers fishing report. Mike Lawson wrote it. This guy’s life time of Henry’s Fork experience more than matches that of ALL HF enthusiasts that walk into his business. When he writes/speaks on the Henry’s Fork, it is time to read/listen.
If I were going to fish the river below the dam and Box Canyon, I would concentrate a variety of terrestrial patterns on board. With respect to mayflies, flavs and PMDs are decreasing in the Last Chance-Harriman reach, but speckled duns are coming on. I’d do the same with respect to terrestrial patterns in the Cardiac Canyon reach, but also have large stonefly nymph patterns on board and hope for some overcast weather (even a passing thundershower (we sure need moisture anyway)) which makes for the best time to present them.