Fall Season River Flows

September 26th, 2018

The Jackson Hole air is finally turning crisp, and with those frosty mornings comes a swing in the fishing. The dam operators have started to lower the flows out of Jackson Lake and Palisades Reservoir, which has definitely affected the fishing bite. Fish are starting to turn away from the hopper, but on cooler and cloudier days there can be some great small dry fly hatches going as well as a good streamer bite. The bread and butter of this time before streamer tossing is the nymph bite, especially on midges such as the zebra midge. The mornings are brisk, with temps sinking to the 20’s and 30’s, but when the water warms up in the day the fishing can be a hit!

Snake River: The hopper fishing has slowed down, but there are still BWO’s and Mahoganies hatching in the cooler and overcast weather. Nymphing has gotten the most hook ups in the past few days since the temperatures have gone down. The flows have dropped significantly on the Snake River the past 2 days, running from 1,800 cfs all the way down to 1,300 cfs today. No doubt that those drops in temperature and flow have had a negative effect on the foam and dry fly fishing, but also be conscious of the changing water in regards to safety. Below is the release schedule for the coming week:

·         Monday 9/24: decrease from 1,800 cfs to 1,550 cfs (decrease of 250 cfs)

·         Tuesday 9/25: decrease from 1,550 cfs to 1,300 cfs (decrease of 250 cfs)

·         Wednesday 9/26: decrease from 1,300 cfs to 1,100 cfs (decrease of 200 cfs)

·         Thursday 9/27: decrease from 1,100 cfs to 900 cfs (decrease of 200 cfs)

·         Friday 9/28: decrease from 900 cfs to 750 cfs (decrease of 150 cfs)

·         Monday 10/1: decrease from 750 cfs to 600 cfs (decrease of 150 cfs)

·         Tuesday 10/2: decrease from 600 cfs to 450 cfs (decrease of 150 cfs)

·         Wednesday 10/3: decrease from 450 cfs to 350 cfs (decrease of 100 cfs)

South Fork of the Snake River: The South Fork has also taken some pretty dramatic flow cuts in the past week, going from 8,100 cfs all the way down to 6,640 cfs today. Those flow adjustments will effect how the fish move and will also move a lot of fish out of their normal spots the more the water drops. In relation to the Snake, the fish are eating nymphs and such but many times refusing the big foam hopper because of the water temperature and weather. Pheasant tails, rubber legs, and midges are great options to drop beneath an indicator or hopper pattern. Don’t forget about the potential for Mahoganies and BWOs in the riffles, as they can bring a strong presence and provide some consistent hook ups.