The lower river (Warm River on downstream) is at its early season best. Remember that it is closed from Ashton Dam to Vernon Bridge until general season opening to protect spawning ‘bows. Here’s the ledger on what is active: BWOs in the PM with overcast conditions being best time. March browns, same conditions best, Caddis life cycle patterns and yellow sallys, any time. Streamers work well in evenings; concentrate on waters out of the sun and with overhead cover. Big stonefly nymph patterns should be in your fly box and they will become increasingly important as we move through the next several days. It’s early to see any adult giant stoneflies. That’s also several days away, but when we get word that fish are keying on them, we’ll pass it on as part of this report.
Flow in the lower river has been mostly stable for many days. Normally this would mean great fishing, but that cotton pickin’ wind messes things up except for very early mornings and just before dark. We think the result is that caddis, BWOs, midges, and March browns emerging there end up in Yellowstone Park where the season is closed. Nevertheless, early and late in the day when the wind slows should be a great time to pitch streamers. Concentrate your casts on the shaded banks or near overhead cover.
I have been fishing the Henry’s Fork a few times this last week and it has been really good. Great insect hatches on the lower river between the Warm River confluence and St. Anthony. The Mother’s Day Caddis are hatching, March Brown Mayflies, and Blue Wing Olives. I tried to find some stonefly nymphs towards the banks and nothing is developing as of right now. I would not expect to see anything like that develop for at least the next 3 weeks. This cold weather we have been having is keeping runoff to a minimum and just slowing everything down for the spring. The good thing about having this weather is we are continuing to put snow in the mountains, and with a bad snow year this will help the fishing in August.
Warmer weather has made fishing the river from Warm River to below St. Anthony a great choice. Remember the closure in effect between the Vernon Bridge and Ashton Dam until general season. There is plenty of access to enjoy the BWOs especially because Fall River runoff has not begun. Weather coming up the next few days should be ideal for BWO emerging in the late PM after winds die. Streamers will be effective up & down the river, and above the Chester backwaters be sure to have big stonefly nymph patterns. Hard to believe, but these big nymphs will begin to move in numbers in about a month.
No March Browns to speak of but we expect them anytime soon. Blue Wing Olives and Midges are hatching really well. Nymphing is also producing good fishing when the dry flies are not hatching. Expect the flies to hatch in the afternoons. Fishing has been really good on the Henry’s Fork, this would be my first pick for fishing on a day off.
Blue Olives have been hatching on the warm days, expect them in the afternoon hours. No word on the March Browns but they should hatching anytime, and I would have some with me just in case. Nymphing is the name of the game for the majority of the day, rubberlegs and beadhead nymphs. Many people are having great success below Chester Dam, down to Del-Rio Bridge. Warm River to Ashton is fishing as well. However I have not heard if the self ice has melted at the Ashton boat ramp yet. A few weeks ago it was about 4 feet high. I would call ahead before you launch your boat.
Fishing on the Henry’s Fork is really good. Blue Wing Olives, and Midges are hatching in good numbers. Nymphing has been really good throughout the day and fish are rising to dry flies in the afternoon. I would also try fishing a skwalla pattern in the afternoon. Zebra midges, rubberlegs, Pulsating Emergers, Harrop’s BWO Emerger are good flies to fish. If you feel like crossing over to what some call the dark side of fly fishing San Juan worms and glo bugs have been really successful.
We received a email from the Henry’s Fork Foundation in regards to the flows below Ashton Dam. Here is the email.
Subject: Ashton Reservoir Drawdown
PacifiCorp has started lowering Ashton Reservoir this morning. If you’re watching the gage below the dam you’ll likely see two increases in river flow of approximately 100 cfs each this morning. The reservoir will lowered to a target of approximately 5147, about 5 feet below the current elevation.
This drawdown is being made in preparation for construction of a new low level diversion tunnel later this year. It is being schedule at this time for the purposes of complying with USFWS consultations relative to the Migratory Bird Treaty Act and in cooperation with the adjacent irrigators on the reservoir who would prefer to not see elevation changes during the growing season.
The drawdown rate will conform to consultation language discussed with IDFG, not more than 100 cfs change in one hour, not to exceed more than 200 cfs change in 24 hours.
So what does this mean for the fishing? I would not be to concerned with these flows upsetting the fishing for very long. Expect it to slow down for a day or two. The fishing will resume as usual after that time. Lots of people have found success using Midges, Rubberlegs, and worms. I would expect the San Jaun Worm fishing to be really good with these increased flows.
Drift boat fishing on the Henry’s Fork is not possible right now because all of the boat ramps are still snowed in. However fishing has been really productive on the Henry’s Fork. Midges are being taken on the surface. Glo Bugs, San Juan worms, Rubber leg stonefly nymphs and Zebra Midges are producing fish in good numbers. As the warm weather continues it will not be long until Blue Wing Olives and March Browns will be hatching. Good places to walk in and fish is the confluence at Warm River, Vernon Bridge (don’t fish above the bridge…its closed!) Sealy’s, Chester Dam, The Fun Farm, and below St. Anthony.