If I could have one month off work a year to fish in the Yellowstone Region, September would be it. The weather cools, the colors change, and big fish are on the prowl as we head into fall. In this blog post, I go over why September fly fishing in the Yellowstone Region is so exceptional.
September Fishing In the Yellowstone Region
Shorter Days and Cool Nights
By September, the dog days of summer come to an end. The days are shorter, and nighttime temperatures cool many fisheries across the region. This brings numerous fisheries back into play, lifting hoot owl restrictions across the state. The longer nights also make it easier to get up early and hunt streamers at sunrise, looking for the big fish that fall is known for. All in all, the weather is much more pleasant for fish and anglers alike.
Diverse Fisheries
The changing weather conditions make September one of the most diverse months for fishing in the Yellowstone Region. However you prefer to fish, you can do it in September. Hopper eating cutthroat, gulpers on the lake, early morning streamer fishing, migratory trout, backcountry lakes and streams, it is all in play during September. With so many options, it pays to be flexible as an angler. Maybe spend the morning hunting streamers for a big brown trout, then get in the car and head to a cutthroat stream for the afternoon terrestrial fishing. I recommend taking advantage of the diverse fisheries and having a few options in mind each day on the water.
Less Crowds
September marks the end of the busy tourist season in the Yellowstone Region, as kids return to school and hunting season begins. While there are still plenty of people visiting and fishing in the area, the traffic is not as bad as it can be during July and August. Getting in and around the park is often easier, and there are fewer crowds at the boat ramps.
With that being said, there are still plenty of anglers on the water, especially on popular fisheries. It pays to think differently and have a few options in mind in case things are too crowded for you. Fortunately, numerous fisheries in the Yellowstone Region fish well in September.
Migratory Brown Trout
September is when my mindset shifts to brown trout after a summer chasing our native cutthroat. Big brown trout are on the move as they prepare to spawn in October and November. Tributaries to lakes and big rivers get an influx of brown trout as they migrate to their spawning grounds. These fish are most often fooled with streamers, as they are hyper-aggressive. That being said, nymphs and dry flies can be productive depending on the weather.
We all dream of catching big brown trout, and September is the best month to target them before they get on spawning beds.
Fall Colors
Yes, the fishing is good in September. I love catching a September brown trout just as much as the next guy. But what really makes September special is the beautiful scenery as the hillsides and valleys change color. Bright orange, yellow, and red shades fill the region, creating some of the most stunning backdrops an angler will fish under. It’s hard to put into words how gorgeous the fall colors are in the Yellowstone Region. When combined with the cool mornings, elk bugling, and aggressive brown trout, September fishing in the Yellowstone Region is a fly fishing paradise.
Match The Hatch Fishing
As water temperatures cool, hatches begin to ramp up for the match-the-hatch angler. Blue-wing olives, hecuba’s, tricos, and caddis are the most prevalent hatches in September, along with continued terrestrial fishing. Depending on the fishery and the weather pattern, one can find epic dry fly fishing during September in the Yellowstone Region. The fish have seen a summer’s worth of angler pressure by this time, so keeping a full fly box, a long leader, and a practiced reach cast will give you the best chance at dry fly success.
A few hatches/dry fly fishing events to look forward to include:
- Flying ant swarms can occur in the beginning half of September on many Yellowstone fisheries. If you’re lucky enough to be on the water when this goes down, you’re in for an epic day.
- Trico mayflies are most notable on the Madison River between the lakes, including Hebgen and Quake Lake.
- Hecuba mayflies are found on rivers such as Slough Creek, Lamar River, Soda Butte, Snake River, and more.
- Hopper/beetle fishing is effective on all rivers, but it’s particularly good on small streams scattered throughout the region.
- Pseudocloeon, a small blue-winged olive, hatches on many fisheries throughout September, October, and November.
Experience September Yourself
At the end of the day, September is great because you get a little bit of it all as a fly angler. Match the hatch fishing, hopper fishing, and streamer fishing are all good depending on the day. One can chase migratory brown trout, rising cutthroat trout, or spooky rainbow trout. You get to do it all with less angler pressure and beautiful fall backdrops. It doesn’t get much better than fly fishing in the Yellowstone Region during September.
I wish you a memorable September on the water. I hope to see you out there.
