Idaho is home to beautiful freestone trout streams. Some of these rivers are large and beloved by whitewater enthusiasts while others are small tributaries that one could jump across.
A freestone is a river that is not impeded by a dam. All rivers (other than spring creeks) were freestone streams before dams were built. Once a river’s source comes from a dam it is considered a tail water. One section of the same river can be considered a freestone and the other section a tail water. For example, the South fork of the Boise is a freestone stream above Anderson Dam and a tail water below it.
Fishing freestone streams is a wonderful experience. The amount of insect life in these types of streams is generally less than that of tail waters or spring creeks. Therefore, fish cannot be picky eaters and are usually quite happy to take a variety of flies. This can often mean non stop dry fly action. A dream for those of us who fly fish.
Most of these streams are located in mountainous regions. The water supply comes from snow pack in the majestic mountain ranges covering much of Idaho. This usually makes access to these streams difficult other than during summer and early fall. Melting snow causes run off (muddy, swift water) in the late spring and early summer making fishing these rare gems possible only during a short season.
I tell people expect to be able to fish freestone rivers from the 4th of July -September give or take a couple of weeks. During large snow pack years runoff could continue through mid July. If the snow pack is below average then freestone fishing could be good in June. Fishing can continue into October as well. However, be prepared for snow storms as the fall progresses.
Fishing these streams is usually fairly easy. The key is finding the fish. Don’t bother casting to the same spot over and over. Cover a lot of water looking for pools, logs, rocks, overhanging brush, and foam lines.
Don’t stress over fly patterns. Again the fish have a limited food supply in these rivers, and they are usually aggressive eaters. High floating dry flies are my favorites. Chubby chernobyls, stimulators, elk hair caddis, and other attractor dry fly patterns work great. Stonefly nymphs, copper johns, midges, and pheasant tails work for sub-surface patterns. You can even throw small streamers.
There are many great freestone rivers in Idaho. The crowds are usually small to non- existent on these streams. I have fished freestones many times and I usually get the river to myself.
Don’t expect to catch huge fish. Life in these freestones isn’t easy and trout can’t pack on the weight like those living in spring creeks or tailwaters. Catching a trout 20 inches or larger in a freestone happens, but don’t expect it to be the norm. However, standing in a crystal clear river with the smell of pine trees is hard to beat, and again, DRY FLIES ALL DAY LONG.
A few popular freestones are Kelly Creek, the Big Wood, and the Middle fork of the Salmon. However, freestone streams cover the mountainous regions of the state. Get out there, start exploring, and enjoy the freestone season while it lasts.