Fishing has picked up in most areas since our last report of August 15th. The weather has moderated from the incessant heat experienced in July and early August. Look for fishing to continue to get better with milder weather and cooler water temperatures.
Upper Henry’s Fork
The stream flow from the dam at Henry’s Lake was reduced from 150 cfs to just over 100 cfs on August 20th. Even at 100 cfs the flow in Henry’s Lake Outlet is above the normal average. More water in the outlet this season has resulted in better fishing. A short walk across the meadows at the Flat Ranch can be very worthwhile fishing hoppers along the grassy banks. The Flat Ranch is owned and managed by the Nature Conservancy and is definitely worth spending time there to help understand the wildlife and their relationship with this working cattle ranch.
Currently it is 36% of capacity. The flow at Island Park Dam is now less than 850 cubic feet per second. This is a little below normal for this time of year. Look for the stream flow to continue to drop in the weeks to come. The Box Canyon is now at a very good level for float fishing as well as wade fishing. We like to use a double nymph set up with an indicator using a larger Rubberlegs, Prince Nymph or Pheasant Tail as the top fly with a small Zebra Nymph as a dropper about 16” below the top fly. Hopper/dropper rigs are also very effective. Streamer fishing has also been productive in the early morning and late evening hours.
Last Chance / Harriman Park
Honey Ants have finally started to come off in strong numbers. Coupled with smaller black flying ants, these terrestrials definitely cause some awesome surface activity. You’ll need size 14 Honey Ant patterns as well as some size 18 – 20 black ants. Other terrestrials including beetles and hoppers have been producing hot dry fly action. The best fishing has been occurring in the morning hours. In addition to terrestrials there has been some very powerful spinner activity with Callibaetis, Tricos, and PMD spinners. Throw in a few slow water caddis and Mahogany Dun mayflies and you have what the Ranch is famous for, complex hatches!
Wood Road #16 – Pinehaven
Most of this water is actually part of the Harriman Ranch. It is different because myriad springs flow into the river from the east bank throughout much of this reach. This changes the complexity of the river. Pale Morning Duns are the name of the game here. Trout are normally very selective on emergers and cripples and the usually ignore duns comparable to a six-year-old and brussel sprouts.
We’ve had a couple of productive guide days floating the Cardiac Canyon stretch below Lower Mesa Falls. The water and fishing methods mimic the Box Canyon. There is good wading access at Riverside Campground and Hatchery Ford (FS #351.) If you are a little more adventuresome you can hike down into the canyon from some of the trails including Sheep Falls (FS #163) and Wood Road #6 (FS #151). Hoppers are very prolific in this section of the river making a hopper/dropper a good bet for hot action.
Warm River to Ashton
This section of the Henry’s Fork consistently fishes great throughout the warm summer season. It produces lots of smaller trout and whitefish with an occasional lunker brown or rainbow. Use a high vis hopper with a bead head or rubberleg dropper. This past week 8 local guides from Henry’s Fork Anglers, Three Rivers Ranch, and the Trouthunter participated in a Henry’s Fork Foundation event called Youth on the Fly. We congratulate Andy Jenkins, Tyler Treece and Alex Kohn for the great job they did representing our outfitting business and helping out with these young people. Everyone caught lots of trout. One of the youngsters landed a colossal 23 inch brown.
Ashton Dam to St Anthony
This section of the year is pretty tough during the heat of the summer. Colder nights have started to bring the river back to life. There is lots of drifting aquatic vegetation which makes fishing very difficult. It makes it hard to fish nymphs and streamer fishing is almost impossible. Hoppers have been productive in the morning hours. Trico spinners have been producing good dry fly fishing in the backwater areas near the mouth of Fall River and the Fun Farm.
St Anthony to Confluence
Trico fishing has been good in the morning hours. Later on try hoppers with a nymph dropper. Things slow down in the afternoon hours when the weather gets hot. As we move further into autumn and the weather continues to cool the fishing will improve. Cooler weather will also decrease the bothersome drifting vegetation.
Henry’s Fork Tributaries
As always, Warm River and the Buffalo provide great fishing for small trout throughout the heat of the summer. Both streams are spring creeks that remain cool enough to keep trout active. The water flow on the lower Fall River was dangerously low but trout seem to have weathered through in good shape. If you haven’t fish Fall River you’ve missed a treat. It is one of the hidden gems in the Henry’s Fork region. Use tungsten bead nymphs dropped about 2 feet below an attractor dry fly.
The Madison has been productive in the section from Hebgen Lake to Quake Lake. Dry fly fishing has been good with spruce fly imitations, caddis and hopper patterns. By this time of year the largest cagiest trout have seen just about every hopper made. You can usually score on those trout by dropping a small black ant or a beetle about a foot below a hopper pattern.
Henry’s Lake has been fishing week near the mouths of the tributaries. Best fishing has been in the morning hours from daylight until mid-day. Use a slow sinking or intermediate line with small leeches or wooly buggers. You can also use a high floating dry fly with a small nymph dropper. The same techniques work on the other area lakes. Island Park Reservoir is getting low and the trout are starting to concentrate near the springs.
Gulper fishing has been productive on Hebgen Lake. Best action is during calm mornings when large trout cruise the surface feeding on Callibaetis mayflies. It is possible to catch trout from shore on the north side of the lake but in most cases you’ll need a float tube, pontoon boat or boat. Best action is to use a dry fly that is easy to see like a Parachute Adams with a size 16 Sawyer PT Nymph as a dropper about 8 inches below the fly.
South Fork of the Snake
Fishing has improved on the South Fork. Riffle fishing has picked up with cooler nights. Trout have been feeding on PMDs, Pink Alberts, and a few larger drakes. Look for small blue winged olives with cloudy weather. There have been mutant stoneflies in the morning and evening hours. Streamer fishing has also been very productive in the morning hours and during cloudy weather.
Yellowstone National Park
There are some good late summer options in the park. Many anglers have written off the Yellowstone River because of the low fish population. While the population of trout is low the quality of the fish is very good. You have a great chance to catch a 5-pound native Yellowstone Cutthroat Trout. Use golden stone imitations, hoppers, wooly buggers and bead head nymphs. Hopper fishing has also been good on the Lamar River and Slough Creek. The Gallatin River has also been producing good hopper fishing.