The leaves are beginning to turn color on the rivers here. Mornings are cool, darkness is falling quicker each night. River levels are approaching winter time flows, elk are bugling, chukars are chuking, and anglers are finding a few hours of Nirvana every afternoon. Autumn in the Rockies is an awesome time of year and those that are out immersing themselves in the warm sun and cool rivers are treated to great fishing and peace of mind that can only be found in the river bottoms of South Central Idaho.
There are four insects to pay close attention to in the coming week. Fall Baetis, Callibaetis, Grasshoppers and the Mahogany Dun. The Fall Baetis is a prolific insect this time of year and an overcast day on the Creek can provide a memory to last a lifetime. This little insect must be replicated, keeping its diminutive size in mind. Fish size 22 and even 24 yellowish / green mayfly imitations. Fish these with lots of dry shake and a Duncan Loop, to get the fly pivoting on its hackle tips while it drifts. This will drive the trout crazy as it imitates the wiggling abdomen of the real insect. To read about this technique in more detail (and a few other secrets) you can check out “Lessons of Fairsized Creek” which is a book on advanced technique I wrote several years ago and is available through the fly shop.
Callibaetis is providing great afternoon action even on sunny days. Cripples and spinners are a good choice to imitate this insect, although a well tied Parachute Adams will also work good. If you fish the slower moving water make sure to fish slow and move slow. Big trout will often cruise about the slower currents picking off these insects as they find them, so unlike traditional dry fly fishing, the trout may not be sitting in one spot rising to the same position over and over. Try to see the fish underwater and cast in the direction of where he seems to be going next.
Grasshoppers are still effective this time of year. There are lots of downstream fish near the Willows and Point of Rocks that haven’t been fished to in awhile and are very susceptible to a Hopper presented with a good sized splash! The harder the fly hits the water, the more attention it’s going to draw. Remember â€“ Long drifts and heavy tippets and set the hook hard!
The Mahogany Dun is one of our favorite hatches of the season, as trout seem to go nuts for these size 16, mahogany colored flies. This fly also is fun to fish in the sense that it can be a tricky hatch to see. Although the fly is big, under the flat light of fall, and with the coloring of the bug, it will often come off as a masking hatch when the Baetis are out. The hatch also has a tendency to come and go every few minutes, making anglers stay on their toes and keep track of what the fish are eating specifically. This hatch is found throughout the river, and is often ignored by anglers in the lower stretches of the Creek. Don’t miss this hatch!
Big Wood River
The Wood is in fine fall shape. The Western Red Quill or Hecuba in some circles, is showing up and should become more prolific in the next two weeks. Big dries like Adams, Quill Gordons, any left over Green Drakes from the spring, and Royal Wullfs and Grey Wulffs will imitate this fly well. Blind fish these patterns and show them to fish rising to the Fall Baetis as well.
The Fall Baetis is showing occasionally and brings fish out in the open that often spend their whole season sitting under logs and banks. The hatch is just that prolific! Gulper Specials are our favorite fly to imitate this little bug. Dave Faltings in the shop also has a few favorite patterns for this fly and can get you set up with some winners.
The October Caddis will be making an appearance soon, so have some Royal Stimulators in your fly box. Much like the big Stoneflies on the Wood, the October Caddis goes under the radar. You won’t see loads of them flying about or hatching, but the fish know they are there and will take an imitation opportunistically.
The Lost is finally at a very wadable flow. Nymphing is the name of the game below the reservoir. Two fly rigs are your best bet. Try to sight nymph fish off the gravel bars at the head of the pools. If that doesn’t work for you fish the pools a little deeper. Keep an eye to the back of the runs as well, as these fish will often slip into the glassy tail outs of the runs when enough Baetis are around. The more baetis you see, the more you will want to turn your attention to using small Pheasant Tails.
Upper Lost River and Copper Basin
Low flows, few anglers and plenty of action can be had with basic attractor patterns. Parachute Adams, Royal Wulffs, Grasshoppers, Royal Stimulators, Red Humpies, Yellow Humpies, and Parachute Ants will all take fish. Lower flows means the lower water will fish better as fish move to the deeper areas in the system with the approach of winter. It was about this time last year when we had two reports of Grayling being caught in the system. If you catch one of these please let us know, also try to get a photo and we’ll make sure it gets on this report!
Little Wood River
The Little Wood is fishing well for mid sized fish with Grasshoppers and Caddis patterns. Swinging streamers this time of year may also produce good sized Browns in the desert, and good sized Brookies above the reservoir.
South Fork of the Boise
Some great Fall Baetis action has been reported on the South Fork. The flows are wadable and fewer and fewer anglers are around. Weekdays can be deserted. Look in the long flat glides for rising fish in the mid to late afternoon. Size 20 Blue Winged Olives (baetis) will take most of these fish when well presented. If you find fish in the side channels, be sure to approach them with a lot of stealth. Long leaders tapered to 6X are not an uncommon choice when fishing the little Baetis on this river at low flows.
Warm Springs, Trail Creek, North Fork of the Big Wood, Penny and Dollar Lake and Lake Creek Lake
There are some fish in these little waters still, and they can be great places to find solitude and beautiful fall colors this time of year. Basic attractor patterns are all one needs. October Caddis can be big players on these little streams this time of the season, so don’t hesitate to throw good sized Royal Stimulators.
Basin Precip. Averages
Salmon – 76%
Big Wood – 88%
Little Wood – 106%
Big Lost – 100%
Henry’s Fork – 88%