Big Sky Anglers Fishing Report 9.30.21
By angelamontana

Posted: October 4, 2021

It’s been busy around Big Sky Anglers the past few days. We had our 4th West Yellowstone Trout Spey Days event on Friday evening and all day Saturday featuring awesome presentations from Simon Gawesworth, Eric Neufeld, Ed Ward, and our own Matt Klara as well as lots of time to play with the coolest Spey gear from all our favorite companies. On Monday and Tuesday, Simon Gawesworth taught two days of amazing Spey instruction with the help of Justin and Matt. We were blown away to see how excited folks were and how much the attendees learned and improved their casting!

At the same time, our guides and shop staff have been fishing all over the Park as well as the Henry’s Fork, the Madison, and other waters. Beautiful Autumn weather has been the norm, and we are waiting for the next blast of scuzzy weather to trigger another burst of perfect “catching conditions”. The weather forcasts suggests that may happen by the middle of next week!

If you’re coming through the area and would a like tour of the Golden Stone Inn, please stop by the shop and let us know. The fire pits are glowing and waiting for you and your buddies to settle in and reminisce.

Big Sky Anglers is OPEN from 7am to 8pm seven days a week. Remember, the freshest fishing report is found at the counter of our fly shop. Our shop staff and guides are out daily all across the Greater Yellowstone Area. Our fly shop remains a clean and healthy environment for both our customers and staff members. Stop on by, say hello, and we’ll get you taken care of. Most importantly, stay safe, stay healthy, and enjoy your time outside.

Take care and fish on,
~ Joe, Justin, Jonathan, and the BSA Crew


Henry’s Fork Streamflows

Island Park Dam: 188 cfs
Ashton Dam: 844 cfs
St. Anthony: 698 cfs

Fall fishing is still going strong on the Henry’s Fork, the river is fishing well from top to bottom. Colder mornings will slow things down until the needle moves up on the thermometer, but water temperatures are conducive to good insect activity on most days. Weather will dictate how many hours of goodness you get out there.

The Box Canyon is a great place to spend the day at this time of year, and it continues to fish well. Flows are hovering around the 200 cfs mark, which makes for a bumpy ride in a few areas, but the fishing is a solid option. Think baetis and midges for nymphs, a rubberlegs is always a good thing to try. Dry/Dropper, indicator nymph rigs, and streamer rigs are all a good idea here. Change the depth on your rigs in appropriate water or choose a depth and focus on that water all day, either plan will work on most days.

The Railroad Ranch has been fishing well and providing many of dedicated Ranch anglers with a fall to remember. Bring your A-Game, your favorite fly rod, a long leader, and a good selection of small mayfly spinners (think tricos and pseudos #18-22), mahogany duns and emergers, a few small dark caddis #18-20, and even a few terrestrials to round it out. This is a great time of year to take your fly rod for a walk in search of some classy angling that can really get your heart pounding.

The canyon country below the Ranch, both above and below the falls, is a great place to be on a sunny day. The canyons can fish well on weather days as well. Temperatures are getting cold enough to recommend that you keep an eye on the forecast if you’re heading into these areas. You don’t want to be deep in the canyon country without the right layers if the weather turns for the worse. Dry/dropper rigs and streamer rigs are the usual fare down here.

Below the Warm River confluence, in addition to being almost 1000’ feet lower in elevation and a little more comfortable than the upper river on the coldest of days, the river is fishing well. We are typically dry/dropper or streamer fishing here at this time of year, but keeping a keen eye out for a snout here and there during a thick hatch of baetis can yield rewards.

Below Ashton Dam, the river is fishing well with nymphs and streamers in the mornings, followed by baetis activity during the midday hours. Mahogany duns make an appearance down here as well and it’s worth keeping an eye out for them. Weather will affect the hatch window, colder days with clouds will often result in better and longer lasting hatches but the bugs can start later than usual.


Not much news in the YNP report this week. Forecast call for more sun and striking blue skies for the foreseeable future.

These are some of the most spectacular days of the season. So, be sure to take some time on the stream bank, or the tailgate to sit back, enjoy a cold one with some friends, and soak it up!

Clear, bright skies are ideal for the chamber of commerce brochure, and epic landscape shots on Instagram, but they are less than ideal for storied fall angling pursuits. There is still plenty of good fishing to be found on these stellar days, you just need to be more targeted in your approach, and be sure to bring your “A-game” to the water.

Fall fishing in YNP revolves around streamer fishing, and fall hatches (mainly Baetis), both of which are better when weather conditions are super scuzzy. However, just because the forecast has you reaching for your SPF instead of your Gore-Tex, doesn’t mean you can’t find some good fall fishing.

On bright days, streamer fishing, especially for migratory fish, will be more productive during periods of low light levels. That means early in the am, and late in the pm. These are the days to be on the water as early as you can. Brave the cold temps to capitalize on a few hours of fish activity, and then take some time to bask in the sun, and enjoy a late breakfast or early lunch. Alternatively, the last few hours of daylight will also see an increase in activity with fish becoming more comfortable as the sun gets low over the western horizon, and shadows grow long and dark across the water.

If it’s especially warm, you might take advantage of the last of the terrestrial season with a few fish on flying ants, hoppers, or crickets. Otherwise, you could find sparse hatches of fall Baetis mayflies will still occur, and prompt fish to feed. Regardless of the dry fly you throw at fish this time of year, remember that these fish have been playing the game since June, and are in no mood for sloppy presentations, clumsy approaches, or the wrong pattern. Take your time, plan your approach, and step up to the plate with your best swing.

Any plan to fish the park waters this week should also take into account the maddening fact that Yellowstone Cutthroat trout, the cherished backbone of angling in YNP, are a worthless quarry until water temperatures warm into the 50’s, at least. Waters that teem with fish willing to rise slowly, and inspect, then yawn on your dry fly to eat it one day will be virtually devoid of life on another if the water temps aren’t high enough for these persnickety, cold-blooded fish to feed. Keep this in mind when heading over to the Cutthroat Corner of the park, and be sure to plan the bulk of your fishing here to the warmest parts of the day.

As always, the corner of 39 Madison Ave in West Yellowstone, MT is the best place for up-to-date info on conditions, flies, and tips before you venture into the Park. Be sure to stop by the shop, and give or get a report.


The flows at Hebgen Dam pretty much stayed the same this past week and we are sitting at 806 CFS out of Hebgen Dam, 919 at Kirby and 972 CFS at Varney Bridge. Fall is in full swing now, cooler mornings will offer a slower start to the day for dry fly fishing but nymphing or streamer fishing is a great option out of the gates.

Wade Stretch:
BWO’s have been seen everyday, but on the cloudy overcast days the hatches have been thick. Purple Haze, Bucky’s BWO Klink and Jojo’s BWO are great choices fished as single dry. Rhyacophila caddis are in the drift everyday and are of the utmost importance when nymphing. Check your boots for these little olive larva as they like to cling. Nymphing with a black rubber legs, #14-18 BH pheasant tails, golden stone nymphs, perdigons, prince nymphs, Cheeky fella(caddis larva), olive serendipities, zebras, shop vacs and crystal dips have been effective in the deeper runs or fish them shallow around the bars and drop off near the banks under a chubby. The Sparkle Minnow has been producing quite well down there, so hav KG’s mini streamers in all shapes and sizes. The BFE is always a good choice when stripping flies.

Float Stretch:
Nymphing from the boat, especially in the cooler morning hours or throughout the day, has been a great option this past week. As we like to say, it’s been pretty nymphy out there on the Madison. Fish are eating rubber legs, scuplins, zonkers, olive hare’s ears, cheeky fella, PT’s, Shop Vacs, guide dips and various Perdigons. For the techy anglers, fishing small BWOs in the slicks will make fish come to the surface for sure. Purple Haze, Bucky’s BWO Klink and Jojo’s BWO are great choices fished as single dry. For those not wanting to stare at a bobber, then rolling the middle of the river, danglin’ a tungsten bead about 2-3 feet under the Hopper will produce. The streamer bite in the morning hours is always a good idea and if it stays cloudy, keep stripping. And if it doesn’t stay cloudy, keeping stripping until you’re blue it the face and willing to tie on nymphs or fish a small BWO in the slicks. We love olive and black streamers this time of the year and white is always a solid choice. Everyone has their favorites, that for sure. We like fishing a 150 grain line with various scuplin patterns like Ivan’s Dirty Dumpster, Sparkle Minnow, Olive Bouface, and the Olive Peanut Envy. KG’s Mini Sex Dungeon in purple/black or the olive are solid choices as well. For those wanting to fish streamers on a floating line all of the above patterns are just fine; toss in the Thin Mint and a BFE to round out the selection. Pinch those barbs!

Please be respectful to those fish that do eat your fly. Land them quickly and take care to revive each fish with your anchor on the bank. Pinch those barbs and learn how to keep tension on the line. Trout pics are something we all enjoy, but if you can avoid it in the afternoons please do so. Get creative with your pics and keep those fish wet. Celebrate the trout in the net and enjoy watching them swim away. We find that a slow mo video is the best way to capture the moment!


Bows and Cuttys are looking to pack on some pounds ASAP and the Autumn spawning species like Browns, Brookies, and Lakers are gearing up, becoming a bit more agressive, and starting to migrate to their final destinations.

The bulk of the stillwater fishing has shifted back subsurface. Go early, stay late, and take advantage of longer periods of low light. Feeding windows are often short late in the fall, but when you hit them, they can be glorious. Hebgen and Henry’s are both great bets these days, just be aware of the changing weather, and afternoon winds. There are few experiences greater than sitting out a hail storm in your float tube. so choose your timing and access points accordingly.

On Saturday, we experienced a fairly light and localized callibaetis event on Hebgen that was enough to get some good trout rising. The following morning, a friend went looking for a repeat in the same area, but nothing came about on top. So it goes in Autumn.

As we get farther into the Autumn, insect hatches will decrease even further, and with that, the important food sources change. Look for fish to really start keying in on high protein food sources like leeches, scuds, and baitfish. These foods will be available more and more as weed beds die off and the trout slide back into the shallows to feed. Impressionistic patterns like Rickards’ Seal Buggers, Stillwater Nymphs, and Balanced Leeches in various colors are staples at this time of year.


Below are links to the flows in Montana and Idaho as well as. This time of the year flows and the weather are changing daily, if not by the hour. Click the links below for the most up to date information.

Montana River Flows
Idaho River Flows
West Yellowstone Weather Forecast

For more information on Big Sky Anglers, click here.