Big activity now is brown trout migration in the Madison, Gibbon, and Lewis rivers and Duck Creek. Later in the month brown trout runs on the Snake and Gardner rivers will kick in. Streamers on sink tip lines are the name of the game on all of these with low light conditions offering the best times to be on these waters. Lewis Lake offers good trolling and shoreline casting for browns near the outlet and through the channel at the north end inlet. Browns are now piling up in the channel below Shoshone Lake, but so are anglers. Some of the Park’s best fishing for browns can be had here if you are the first one of the day to venture in. If you prefer dry fly fishing, the Firehole River is fishing very well with BWOs and caddis leading the way. Jack Frost has pretty much nipped most hopper fishing at the bud, but a few can be found around Fall River Basin streams. Speaking of Fall River Basin, Beula Lake fishes well on bluebird days this time of year. Use small bead head nymphs, Midge pupa patterns under indicators or small leech patterns.
Fishing on the Firehole river is picking up with BWOs, tricos, & caddis attracting fish. But a cold snap in needed to really get things going. Elsewhere good terrestrial insects are numerous as there has been no blanket killing frost. This begins the time of year when brown and brook trout are on the move to spawning areas. Streamers are the way to encounter them, especially the big browns. These are moving into the Madison River above Hebgen Lake, but waters are warm enough that good action is in the future. It’s much the same with the Lewis River system; A touch of cold weather would bring on best action from migrating browns. C’mon cold snap!
Some higher country frosts are beginning to nip terrestrial insects, but good populations of these exist on most streams. This includes Fall River Basin streams, Slough and Soda Butte creeks, and the Lamar River in the meadows. Fishing on the Firehole River is picking up with hatching tricos, BWOs, mahogany duns, midges, and caddisflies providing action. The big event for this time of year is migrating browns in the Madison, Gibbon, and Lewis rivers. Low light conditions will be best for encountering these great fish, and streamer patterns are the flies to use. Particular patterns are not as important as having some in light and some in dark colors. For some reason, yellow or chartreuse colors in these flies seem to entice strikes. Looking for still water action in the Park? Beula Lake remains the best place to find it with a few gulpers still working, and damselfly nymph patterns sure to bring responses. Best fishing on Lewis and Shoshone lakes this time of year is for migrating browns around their outlets and Lewis Lake’s inlet.
Crowds are down and insect pests are nearly gone, too. Hebgen Lake fish are in the Madison River, Bechler Meadows, Slough Creek meadows and Black Canyon of the Yellowstone River are full of hoppers and tricos, same with the meadow reaches of the Madison River, Duck Creek browns are on the move, Lewis River system browns are gearing up to do the same, the weather is cooling enough for the Firehole River to be in good fishing shape. So good fishing related things are happening here. It’s probably the best time to be fishing in the Park.
A big visitor weekend is coming up with Labor Day, so expect company, even in some back country locations. Whatever streams you choose, terrestrial patterns are a must. This is really true if flying ant swarms are where you fish. Be sure to have some cinnamon ant patterns in size 14. Look for tricos to dominate AM fishing along some parts of Fall River Basin streams and the Madison River drainage. Slough Creek will feature a green drake emergence. We need to cool off more for the Firehole River to shape up to fall fishing form. Run-up browns and ‘bows from Hebgen Lake are beginning to show in the Madison River. Gulpers are still active on Beula Lake, but expect crowds on this last big weekend of the summer season. Small streams such as Obsidian, Cascade, and Polecat creeks host eager trout for light weight equipment fans. So there will something for whatever your fly fishing preference may be.
The season for using terrestrial patterns continues. Whether hoppers, ants, beetles or spruce moths: all should have representations in your fly box when you visit Park streams. Because slower water is not as well oxygenated as that in riffles and runs, be sure to work these over, and expect more larger fish to reside there until we begin cooling off. Look for tricos to become increasingly active and important to fish as we move through late summer. There are terrific trico hatches and spinner falls on such as the Madison River and all Fall River Basin streams. Lakes are tough fishing now with Beula Lake being the big exception. Fishing there is good because of gulping cutts. All you have to do is walk a few miles and get speckled dun emerger and dun patterns onto the lake beyond shoreline lily pads. Carrying a float tube to get out on the lake guarantees some great action.
It’s terrestrial season on most of Park streams. Want to see how good your skills are with terrestrial patterns? Here’s a few ” graduate school for fly fishers” waters this time of year: Duck Creek, meadow reaches of Bechler River, meadow reaches of Fall River, Slough Creek, Soda Butte Creek, Lewis River below Lewis Falls and between Lewis & Shoshone lakes, and the meadow reaches of the Gibbon River. Want to try some small Park streams with good chances of action and the same with respect to solitude? Try Polecat Creek just west of the South Entrance, Cascade Creek, a tributary to Fall River off the Ashton-Flagg Road, or Winter Creek in the upper Gardner River Drainage. If you prefer still waters, we have been saying it all along: Beula Lake offers some of the fastest fishing in the Park. Speckled dun and midge activities make for gulper action. Any time now flying ants will be around, and every fish in the lake will be near the surface looking for them making for even better gulper action. You can find action almost as fast on Riddle Lake, too.
Terrestrial patterns are the way to go on all streams. Choose one you are sure to see on swifter streams, and delicate ones for slower waters. Horseflies and deer flies are rampart throughout. No better pattern exists for simulating them than a standard humpy! Another terrestrial pattern that is sure to work along wooded reaches are ones for spruce moths. This is the peak of their season, and trout know it.
Fastest action in the Park is from Beula Lake. Gulpers are going, and will continue through the month as speckled duns are emerging. Yellowstone cutts are present, and they range to twenty inches. It’s a 2.75 mile walk from the trail head across the road from the upper end of Grassy Lake Reservoir. Packing a float tube gets you into the best fishing. If walking this far with a float tube and other gear is not for you and you want fast fishing, try Obsidian, Winter, Indian and Panther creeks at the top of the Gardner River drainage. Want to try larger streams? Bring all your skills as this is the time of year when all are reaching base levels and trout become quite selective. This applies to Fall River Basin streams, Slough, Soda Butte, Duck and Grayling creeks, and the Lamar, Gibbon, Snake and Lewis rivers. Run-off from thundershowers can cloud many of these for a time, but after they clear some great fishing can be had. Try big hopper patterns after these as winds blow them around. Also because some bank erosion goes on, going back to patterns that simulate earthworms and grubs are good for a while.