Compared to our numerous more renowned still waters Horseshoe Lake is almost on the “Where’s That?” list. It is remote, not frequently fished, has (at best) primitive facilities, and hosts no self-sustaining salmonid population. But Horseshoe Lake has an attraction no other eastern Idaho water can boast: Montana grayling. The lake has no inlet and outlet needed, in suitable condition, for their spawning. Thus its stock of grayling is replenished each year from a Montana hatchery ( rainbow trout released here come from an Idaho hatchery). A resident grayling here is a “braggin’ fish” if it grows to a foot long, nevertheless they are beautiful to behold, and because of their near endangered status a privilege to catch and release. Resident rainbow trout, also stocked, outnumber them here on a near 10:1 basis, so patience is required to encounter one. The lightest weight in fly rod systems is most appropriate for presentations, and “small” applies to fly patterns. Standard nymph patterns with or without bead heads and soft hackled patterns, both in size 16 or smaller and presented on a floating line and long slender tippet are good choices for achieving interest from grayling. However during wind-free times when rise forms are numerous, nothing beats presenting small (#18 and smaller) dry patterns such as adams, light cahill, and purple haze, all in more visible parachute form, to these fish. You may have to get through several rainbows of similar size before one of these strikes. That makes catching and releasing one even more of a privilege.
Horseshoe Lake is about twenty-five miles east of Ashton. Its road, winding northeasterly, leaves the Cave Falls Road about a mile east of the LDS Church’s Rock Creek Girl’s Camp. It’s a fairly rough road with pot holes, rocks, and lots of dust. Tires in good shape and cautious speeds are required. There are a few non-motorized boat launching sites at the northwest corner of the lake, and flotation devices are most suited for fishing. The best chance for action is through locating in front of the west side lily pad beds where fish cruise looking for emerging aquatic insects. Good Luck!