The Gallatin River near Big Sky and Bozeman is fishing great on attractor dry flies with bead droppers. Water temps are good all day in the canyon but in the valley the heat up fast so be careful of fishing later into the day if you are down low. The morning fishing has been better than afternoon and spruce moths are on the water in the morning before the sun gets too strong. Nymphing smaller patterns on 5x flourcarbon can be effective when they aren't chasing spruce moths up high or hoppers down low. Nymphing the deeper runs with a stonefly on top and a smaller mayfly nymph on point is also very effective. The Gallatin River should continue to provide great fishing for the next few weeks. The trout are still in the softer water along banks, rocks and it tailouts. Fishing is best in the later morning and mid afternoon when water temps are ideal and trigger hatches. Trout are eating both dries and nymphs. Attractor dry flies are just starting to produce and a dropper rig is a nice option. In the deeper runs try running a nymph rig with a stonefly trailed by a smaller bead head attractor nymph. Cover a lot of water but pay attention to where you are finding trout. They are still giving preference to slower flows while the water temps are rising and are not in the fastest riffles yet. The wade fishing can still be challenging with the higher flows.
Flies for the Gallatin River for the Next Few Weeks:
Perdigons #14-18
FKA Prince #12-16
Blowtorch #14-18
Flutter Bug #6-8
Chubby #8-16
Foam Run Caddis #14-16
Mini Dungeon #4-8
Sculpzilla #4-8
The Month Ahead:
The Gallatin River will continue to fish well during the low light hours. As flows drop and the river warms the peak fishing window will slowly move to earlier in the day and morning fishing will out produce afternoons.
Long Term Fishing Forecast
The Gallatin will be a good option in late summer and fall. In the fall the valley fishing improves as temperature drops. Baetis hatches in late September and October can produce some dry fly action.