The Clark Fork river is broken up into two very distinct river sections. The upper river east of Missoula and the Lower river west of Missoula after the Blackfoot and Bitterroot River join its flows. The upper Clark Fork snakes its way through open country and cattle ranches. It’s undercut banks side channels and drop offs provide ideal habitat for it’s predominantly brown trout populations. The lower Clark fork below Missoula has a completely different feel in contrast to the upper river. Long wide runs, riffles and flats hold rainbow, brown and cutthroat trout. The lower Clark Fork has some of the best dry fly fishing in the area because of its abundant hatches that keep the trout looking up throughout the summer. The trout on the lower Clark Fork are some of the hardest fighting in the state.
Streamers and large dry flies dominate the fishing on the upper Clark Fork. Undercut banks with overhanging grass can produce some really memorable dry fly takes. Terrestrials, Caddis and Stoneflies provide most of the surface action on the upper Clark Fork. The lower Clark Fork is a whole different story. The abundant hatches that bring pods of fish to the surface require long drag free drifts, stealthy approaches and exact imitations. Nymph and dropper fishing can be quite productive as well. Finding isolated areas where the trout congregate such as around springs and creek mouths provide consistent nymph fishing. Fishing with streamer patterns can also be extremely effective on both the lower and upper Clark Fork.
Pre Runoff March – May The upper Clark Fork can fish very well early season with streamers. However fishing conditions, water clarity and flows can change daily. The lower Clark Fork is more ideal this time of year. Excellent hatches of Blue Winged Olives and Skwalas can produce excellent dry fly hatches and a nice alternative to the Bitterroot.
Summer June – August The upper Clark Fork fishes well throughout the summer with caddis and terrestrials. Isolated stonefly hatches occur below the confluence with Rock Creek and offers more consistent fishing on the surface. High water temperatures and aquatic grass can create less than ideal fishing condtions on the uppermost sections of the Clark Fork during some years. The lower Clark Fork is at it’s best this time of year. A continuous cycle of mayfly hatches including pmd’s, tricos and drakes. Caddis and terrestrials produce a consistent diet throughout the summer as well. Terrestrials fished in tandem with dropper nymphs is always a good bet in the dog days of summer.
Late Summer/Fall September – November This is probably our favorite time of year on the lower Clark Fork. Hopper and trico hatches continue into the fall and then give way to BWO’s and mahoganies. Bwo’s and mahoganies can produce some of the best fishing of the year. Streamer fishing comes back into play as well. As the water cools on both the upper and lower rivers fish can become very aggressive and become eager to chase down a streamer.