Western Montana Fly Fishing Seasons
Late Summer / Fall Season: September through October
Hecuba (Fall Drake) #10
Mahogony Dun #12, #14
Blue Winged Olive #18, #20
Hoppers and Terrestrials
Ahhh... Autumn. The best time of year (in my opinion) to be in the Northern Rockies. The Summer heat has passed and the weather becomes very pleasant. With the cooler evenings and more rain showers at this time of year, the rivers produce a resurgence of mayfly activity, starting with my favorite hatch of the year, the Hecuba or Fall Drake Mayfly. This size #10 orangeish, tannish, olivey bug must taste particularly good because the trout love them.
During this hatch we not only see more trout rising to our dry flies but a significant number of larger trout as well. The Hecubas start first and then the Mahogony Duns and Blue Winged Olives again. Many days in the Fall see multiple hatches occur with fish rising for hours in the foam lines and pools to the aquatic insect matter on the surface of the water.
Late in the Fall Season as the weather turns even cooler, the Blue Winged Olives prevail. Even well into October, there can be excellent dry fly and streamer fishing for big Browns preparing to spawn.