Big Lost River, September 10th, 2022
Flow out of Mackay Dam is about 200 cfs meaning wading the river below safe. As weather cools, look for BWO activity to increase to attract trout along with terrestrial insects doing the same.
Flow out of Mackay Dam is about 200 cfs meaning wading the river below safe. As weather cools, look for BWO activity to increase to attract trout along with terrestrial insects doing the same.
Cooling and upcoming unsettled weather is just what is needed to bring back daytime action on the lower river. BWO and mahogany dun activity will be on the increase, and barring a killing frost, hoppers and other terrestrial insects will continue to attract trout and steamer patterns will be effective during low light conditions. Until killing frosts take place presenting terrestrial insect patterns is a best straregy for fishing the entire river
On the upper river, Box Canyon will begin producing some great streamer fishing to go along with good results from presenting large nymph patterns, and the same can be expected in the Tubs area below Big Springs.
About a week ago flow out of Henry’s Lake was reduced to around 35 cfs from around 150 cfs. That action will move larger fish out of the Flat Ranch reach of the river and into the river above Mack’s Inn. Look for many of those fish to reside in the Tubs area of the river.
South Fork Below Heise Hot Springs
Higher than normal flow (11000 cfs at Irwin,16000 cfs at Heise, 8500 cfs at Lorenzo ) has slowed fishing success. However, unsettled weather is predicted for much of next week. That’s just what is needed to begin the fall mayfly period. It means a big increase in BWO and mahogany dun activity with fish responding accordingly. Also, do not overlook presenting streamer patterns during accompanying low light conditions.
Another “plus” for fishing the South Fork will be the soon-to-begin advance of fall colors along the river and surroundings. So consider taking that camera during upcoming visits.
The comments we made on the impact of shorter daylight hours and cooler nights applying to the South Fork and the Henry’s Fork with respect to improving fishing conditions also apply to our irrigation reservoirs. Diversion for irrigation purposes will decrease meaning more impounded water which will cool enough to move fish away from depths to seek food forms being more abundant in shallower water.. .
Teton River in the basin offers some good fishing because of ongoing PMD, caddis fly and terrestrial insect activities. Recreational traffic is decreasing as summer transitions to fall.
Warm River Spring
With respect to the insect activity mentioned above for the Teton River, the same is ongoing in the Warm River below Warm River Spring downstream to the top of the cascades. There will be no recreational boaters here and fewer anglers. Thus this part of the river offers a better chance of solitude than present on the Teton River in the basin.
Upper Meadow Slough Creek
The Northeast Entrance Road remains close to vehicular traffic from the Slough Creek campground turn-off to the northeast entrance. This means fishing Soda Butte Creek and Lamar River in its meadow reach and Trout Lake can be approached only through hiking and bicycling. Slough Creek’s upper meadows offer excellent fly fishing because of terrestrial insect activity, but great alternatives are the Fall River Basin streams which have very similar meadow reaches offering the same terrestrial insect activity and AM trico activity.
This guy deserves his share of the fish
Increases in flow of out of Palisades Dam have slowed fishing a bit. Although lower flow remains on the lower river because of diversion for agriculture, shorter daylight hours and lower night time air temps will soon cool this part of the river to help bring on the fall mayfly season there. Mutant golden stone activity is decreasing, and when cooler and cloudier weather begins, our fall mayfly activity will start up and down the river. Meanwhile, terrestrial insect activity provides action up and down the river. Hopper-dropper combos remain a good choice when such are presented toward well vegetated banks.
Visits to the upper river are decreasing significantly, and presenting terrestrial insect patterns is the best way to find daytime fishing success. Speckled dun and caddis activity provide lesser daytime action while tricos bring on early in the day action before increasing air temps awaken terrestrial insects. With shorter daylight hours and colder nights, water in the lower river will begin to cool to the point that fall may lfy activity will begin.
Headlines from Dr. Rob Van Kirk’s Henry’s Fork drainage status report of yesterday follow. :
Rob Van Kirk, Ph.D.
Senior Scientist
P.O. Box 550
Ashton, ID 83420
208-881-3407 CELL
208-652-3568 FAX
Gulpers are still chasing speckled dun and tricos in the Madison Arm and along the south shore of Hebgen Lake during AMs. Consider that other lakes in this part of Montana also have gulper action this time of the season.
As with so many steams this time of year, terrestrial insect patterns are best bets for action on the Gallatin and Madison Rivers. Include spruce moth patterns in that fly box..
Slough Creek, Second Meadow Above the Campground
Here is a suggestion that applies to fishing all Park streams: presenting terrestrial insect patters is a must. Only exception is the Firehole River whose waters have yet to cool to the point where fish caught an released have a great chance of surviving this ordeal.