The beginning of fall is always a good time to pick our flies that will be hot during September and October.
There are still several good insect hatches during these two months and two in particular that only happen in September and October. The Mahogany Dun hatch is always a big hit for fly fishermen. The hatch usually starts during mid September and continues through October. The Mahogany dun is a darker brown than the Green Drake (mayfly) hatch and much smaller. The green drake hatch occurs during the spring months and is a dark olive. It is usually tied with a #10 or #12 hook and looks mighty large on the river. The mahogany Dun is much smaller than the green drake and the best patterns are tied on a #14 or #16 sized hook.
The other pattern that is hot in the fall is the October caddis or commonly called the orange caddis. This caddis is much different from the other species of caddis because the nymphs are found clinging to large rocks in the river. During the regular summer flows the nymphs are nice and safe but when the river begins to drop in the fall a lot of the nymphs are left high and dry. These caddis don’t live and will never emerge for the regular hatch. The ones that are left under water hatch rise to the surface and fly away if not caught by the fish. This particular species is larger than other species and has a brighter orange body.
The October caddis is tied with an orange body and sometimes a small salmonfly pattern will do the trick. A #8 or #10 hook is preferred and one of the best patterns that I use is the orange humpy.
We can’t forget the trico and the blue winged olives that hatch between now and the end of October. The fall BWP is smaller than the hatch in the spring and a #!2, #14 or a #16 will do the trick. We haven’t had a serious frost yet so the terrestrial patterns like hoppers and ants are always a good bet for fishing from now on.
The Bitterroot has produced some great fishing throughout the summer the pressure from fishermen has once again been hard on the fish, especially the West Fork area.
Now that school has started and most families are through with their vacations the Bitterroot local fishermen can appreciate fish with a little more solitude. The fish are really stocking up on their food intake in preparation for the coming winter months.
Floating is still good on the upper river. Flows are about 300 cfs at Darby and the water temperatures are 55 degrees or less. Once we settle into the winter flows the level at Darby will shrink to about 250 cfs and you will have to drag your raft a few times in these stretches.
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