Big Sky Anglers Weekly Fishing Report – 9/1/2022

by | Sep 8, 2022

Hello from West Yellowstone, Montana
– The Trout Capital of the World –

Holy smokes, September is here folks! Not to worry, summer is sticking around for the time being, but after next week we expect things to cool off and feel a little more like Fall. It may be a bit chilly in the morning but by noon, the high sun will shine down and give way to warmer temps and wet wading. Heck, you might want to even soak those bones and cool off around 3pm or so, don’t forget to re-apply that sunscreen if you go for a dip. We love all that the transition from summer into autumn brings. Hoppers and ants, bugling elk, tiny dries and nymphs, big streamers, Spey rods, and swung flies, brown grass, green pines, and golden aspens. It’s September, baby, and it’s all happening!

A reminder to everyone that our annual Trout Spey Days event is scheduled for September 9th and 10th, and is sure to be a good time as always. Lots to learn this year from our great lineup of presenters that includes Simon Gawesworth, Eric Neufeld, Lee Davison, George Cook, and Matt Klara. Head over to the event website via THIS LINK to get all the details. The presentation schedule was modified this past week to best take advantage of our time at the river. Call us at the shop to get signed up. Spots are filling up!

If you haven’t already, now is the time of the year to start planning your fall fishing trips to West Yellowstone, Montana. Give the shop a call or shoot us an email, we’d love to help you plan your trip or suggest some flies to tie up for September and October. If you haven’t walked in the fly shop this season, take a walk downstairs the next time around and check out the new fly tying section of the store. We have filled the Travel Lounge with tying materials and if you are in need of a place to tie some flies, there is table, light and vice waiting for you.

For the freshest report, be sure to stop by the shop at 39 Madison Ave in West Yellowstone where you’re sure to find a few sun-burned trout bums, bleary-eyed from fishing the previous night’s hatch well into dark, and plum full of more good info and passion than any other staff around. While you’re there, don’t miss our newly expanded fly tying lounge in the basement. You just might catch Hoovie or one of our other bug-obsessed fly winders at the vise answering fishing’s great mysteries with fur, feather, and thread.

Big Sky Anglers is OPEN from 7 am to 9 pm seven days a week.

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,

The BSA Crew

Weather Outlook 
Daytime highs for the upcoming week look to be in the high 80’s, with minimal chance of rain. Nighttime temps will be into the low 40’s, so expect to don a layer early in the day only to shed it before lunch. As always, bring that rain jacket with you as you can never totally count out an afternoon thunderstorm in the high country. You likely won’t need waders this week, but next week thats gonna change.

Henry’s Fork River by Jonathan Heames

Island Park Dam: 930 cfs

Ashton Dam: 1550 cfs

St. Anthony: 1300 cfs

Fall River: 339 cfs

Summer is hanging on here in Henry’s Fork country, this coming week we expect to see warmer than normal temps, maybe even a record broken for a high temp! The nighttime temperatures are dropping down so there is some relief. The fishing continues on the upward trend, but this weeks warmer than normal temps might slow things down to some extent, hard to tell right now. River wide, clarity has improved quite a bit this last week and the river is in good shape at the moment. Weeds are a part of daily life, knowing how to deal with them on your flies will help to keep you an efficient angler out there.

Box Canyon: Flows and clarity are in good shape in the Box Canyon, and it is fishing well. Now is a good time to be thinking not only of the bugs that you’re imitating but the colors that may trigger these fish into action. Red and brown zebra midges 14-18 are a staple in here this time of year. Mayfly imitations should be smaller, 16-18, generally. We like PTs, Olive Hot Spots, Duracells, Bullet Quills, and Jig Napoleons for this. An Olive Hungarian Partridge Caddis Pupa in a 16 is a good bet for the few caddis that are around these days. Streamer fishing is a good option in here, we like a Copper Zonker, Olive/Black BFE, Bouface Leech and white Sculpzilla.

Railroad Ranch: The Ranch is beginning to show more signs of life as we near the end of August. Good spinner falls in the mornings, with both honey ants and small black winged ants sprinkled about are contributing to more trout seeking their food on the surface. Water clarity has greatly improved overall and this is helping the midday hours’ terrestrial fishing. Trico and pseudo spinners in 18-20, Callibaetis spinners 14-16, Harrop’s Honey Ant 14-16, Shimazaki Ant 18 will have you covered for most situations. Mahogany duns are right around the corner, now is a good time to make sure you have a couple of patterns 14-16 in case you’re on the water the day they decide to show up to the party.

Canyon Country: It remains a great time of year to enjoy some of the solitude that can be found in the sections of river above and below Mesa Falls, water clarity is good through these sections and the aggressive water keeps the trout bitey. Hopper/dropper rigs are a good choice, as ever, but don’t leave the streamers behind when heading down here. A proper reminder is in order for anyone headed here that skilled oarsmanship is a must, and a raft is highly recommended, even required for the water below the falls.

Warm River to Ashton: This section continues to provide most visiting anglers a fun day of fishing with decent action throughout the day on small to mid-sized trout. Larger trout can be found by searching with a hopper pattern or by committing to streamer fishing for the morning hours.

Below Ashton Dam: The lower river is generally not where we’d steer anglers at this time, flows are decreasing and daytime temperatures are still high. It can be worth a foray in the morning hours, but after noon your time will generally be better spent upriver.

Have a great week out there!

Madison River by Dinah DiMeolo

While September is welcoming us with significantly warmer weather than we might like, the fishing is definitely picking up here on the Madison. Water temps at Kirby have been dipping into the mid-50’s the last several evenings which has been a beautiful sight to see. Additionally, there’s been a slight bump in flows this week- 1190 CFS running at Kirby and 1310 CFS at Varney Bridge. These next few hot days will be important to continue fishing early in the mornings, but as the week cools off again afternoons may become very productive.

You may find a few sporadic mayfly & caddis hatches fluttering around this time of year, and covering water with a single dry may help you find fish along the banks or other softer water. I would go back to the basics and suggest throwing #14 or #16 PMD patterns, X or Iris Caddis, or a trusty, old-reliable Rusty Spinner. With cooler mornings in the forecast, expect to be fishing small dries from mid to late morning, and plan to change your setup once the afternoon heat arrives. Ants and hoppers are still abundant along the Madison, so once the morning hatches settle down, try tying on a dry-dropper with a Thunder Thigh, rootbeer or purple Chubby, or Jojo’s Ant, down to a perdigon or other tungsten nymph. As the season goes on, fishing with utmost delicacy and stealth in the shallow margins or, really dropping heavier bead head nymph bombs to the bottom in the deeper heavy water are 2 solid approaches. Make sure you have a bouyant enough hopper on top to compensate for that weighted nymph. You don’t want to blow you shot at a good drag free drift with the hopper in the name of indicator nymphing.

Be well prepared heading out on the water these days, as afternoon storms can sneak up on you quick. I wouldn’t want to have to leave the river from being cold & wet and end up missing a good ant emergence, so have a raincoat, check the weather beforehand, and plan accordingly. Success is when persistence meets preparation, so have your bags packed, a positive attitude and go find fish.

Yellowstone National Park by Patrick Johnson

Change is usually the name of the game this time of year — as we head into September, I almost start to resent the heat at this point, drooling instead over memories of Autumns past in anticipation of what’s to come: cool temps, evenings spent tying by the fire, and short brisk days stripping streamers in the park for large, migratory trout. Unfortunately for us, it looks like the pendulum of change may be swinging in the wrong direction over the coming days. While we’ve been blessed with cool mornings and a handful of those iconic late-afternoon thunder and rain storms recently, Autumn still seems way off, with next week’s forecast calling for consecutive cloudless days and temps in the high 80’s.

With that said, we anticipate terrestrial fishing to remain stable and steady throughout the Park this weekend, with the caveat that your angling plans should remain flexible and adaptable: Don’t keep all your eggs in one basket, nor all your flies in one river. Instead, I suggest switching it up and moving around throughout the day to find where they’re eating best. Despite the sweltering midday temps, cool evenings and mornings should persist with little to no cloud cover to trap the heat in — one might try throwing hoppers and ants around the Madison Junction or Gibbon Meadows in the morning, and then heading to cooler, higher-altitude water after lunch (e.g. the Gallatin or Gardiner). Once the sun is high overhead, and the fish have abandoned the surface in favor of those cooler, deeper runs, you can always nymph deep with the much-beloved double-nymph indicator rig. We’ve hooked those pickier, bottom-dwelling trout over the past few days on size 16 and 18 soft-hackled perdigon nymphs (I like the Jig Duracell in UV Purple, Tan or Rainbow) hung below a larger, size 12 Tungsten Pheasant tail. While it might not be as fun as seeing those fish envelop your dry, sometimes you have to prospect the depths.

With all that said, it’s also worth noting that the park’s backcountry stillwater scene remains alive and well — damsel, caddis, and mayfly eaters have stuck around throughout the afternoons recently, and it’s important to keep these options in mind when bouncing around the park in search of active fish and cool water.

While hoppers, beetles, and ants remain the number one food group for the park’s trout, all you fall-fishing streamer junkies out there will be happy to note that cooler morning temps have also meant an increasingly good morning streamer bite. Now is a great time to get out there early and start practicing those strip-sets. While it hasn’t necessarily been lucrative yet, whispers of patient, early-rising anglers hooking into large trout on darker leech and bugger patterns (stripped) or larger spey-style flies fished on the swing have started to filter into our fishing conversations here at the shop.

Stay up to date on YNP roads below


The Lakes by Matt Klara

We’ve been seeing some great fishing on Hebgen Lake lately. Callibaetis hatches have been strong, with good spinner falls, and finally the trout are in “gulper” mode, patterning their rises. When the trout are putting only two and three rises together in sequence and then disappearing, we are still dropping a nymph below a dry fly or stripping a nymph across the target zone. When they are linking up their rises and staying near the surface, it’s time to go to a spinner pattern, they’ll often shun the nymph at this point of the hatch, usually around late morning or early afternoon.

As this summer weather continues, the lakes in this region will continue to fish well with callibaetis, damselflies, and terrestrial patterns. We are now expeiencing more consistent flying honey ants (#14) on the water as well. Any time you find these guys, there are trout eating them, so don’t be caught without the right fly!

If you find yourself out there with no surface activity, remember that it’s hard to go wrong with a chironomid and a general nymph fished static, or a slow stripped leech or callibaetis nymph.

The backcountry and higher elevation alpine lakes are very much still in play, though some of the aquatic insect activity is really beginning to drop off. Once that happens, look for terrestrials during the warmest parts of the day and otherwise fish subsurface with leeches, scuds, and dragonfly nymphs that have multi year life cycles and will trigger a trouts urge to feed. Up in the alpine, September means that winter is coming.

Regardless of where you are fishing, be aware of water temps. Lake fish are particularly susceptible to C&R mortality if temps climb and dissolved oxygen levels drop.

River Flows and the Weather Forecast
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