Classic fall conditions are on tap again this week in Yellowstone Country, with a few warm, beautiful days followed by some more cool, wet ones. Sunny days pushing 70 degrees will be great for some late-season terrestrial fishing, while gray days in the 50s will produce some more of those fall hatches and streamer sessions we all hope for this time of year. It's going to be a fun week to be fishing around the Park. 

HERE ARE THIS WEEK'S STANDOUTS. 

FIREHOLE RIVER

The Firehole has settled into a standard fall routine of daily baetis mayfly hatches and rising fish. Some days have a stronger emergence (scuzzy days); others are sparse (sunny days), but bugs are hatching somewhere along the river every day, and fish are feeding on them. 

As is always the case in the fall, these 10-12" browns and rainbows will test your skill and humble even the most veteran anglers. Come prepared with long leaders in 10-12' lengths, tippet sized down to 5.5 or 6x, and a stealthy, delicate dry fly presentation. 

These are some of the most challenging, and rewarding dry fly targets of the entire season, and every so often, you will be surprised by a fish in the 16-18" or bigger size class. 

MADISON RIVER

More and more lake-run fish are moving into the system with each passing day, and as October nears, we inch ever closer to prime time on the Madison in the Park.

It will be important to keep an eye on conditions this week and adjust your plan accordingly. Sunny days will require an early morning start or a late afternoon session to take advantage of lower light levels and a better chance of finding active fish. Spend the bright afternoon chasing terrestrials in the Northeast Corner, then slip back to the Madison in the evening on your way out of the Park.

Scuzzy days should encourage a fresh push of fish into the river and provide your best opportunity to find good fishing throughout the day. Cloud cover, cooler temperatures, and unsettled weather will give you more freedom to fish the Madison beyond those early and late windows.

GALLATIN RIVER

With a variety of weather conditions in store this upcoming week, there may be no more versatile a river to fish than the Gallatin in the Park. No matter the weather, there's a great game to play here.

Warm, sunny days are the time to reach into the terrestrial box for possibly the last time this season, drifting small hoppers and ants through tight pieces of slow water along undercut banks. Gray, overcast afternoons are the time to watch those same pieces of water for subtle rises from brown trout taking Baetis emergers just below the surface.

And when the fish aren’t looking up, the nymph fishing is outstanding. Riffles, runs, and deeper pools all offer productive opportunities, making the Gallatin one of the most consistent options in the Park this fall.

SLOUGH CREEK

Terrestrial season is winding down on Slough Creek, but we’re not ready to close the book just yet. The nicer days ahead may offer a few more opportunities to tempt cutthroats with small hoppers, beetles, and ants, especially during the warmest part of the afternoon.

At the same time, fall mayflies are taking center stage. Baetis, Heptagenia, and Hecuba continue to provide some of the most interesting fishing on Slough, particularly when clouds and cooler weather settle in. Sight-fishing can be more challenging under gray skies, but a good emergence will reveal feeding fish. Look for the best activity during the afternoon hours as water temperatures warm and mayfly activity builds.

LAMAR RIVER & SODA BUTTE CREEK

The other pillars of cutthroat fishing in the Northeast Corner of the Park, the Lamar River and Soda Butte Creek, are in much the same boat as Slough Creek. Terrestrial season is waning, but there are still some good days in the upcoming forecast to take advantage of.

Don’t expect to see much happening before late morning, or even early afternoon, especially after nighttime lows drop into the 30s. Give the water some time to warm and the fish a chance to become active before reaching for the terrestrial box. Small hoppers, beetles, and ants remain good choices, but expect the window of productive dry-fly fishing to become shorter as we move deeper into fall.

On cooler, cloudier days, keep an eye out for Hecubas and other fall mayflies. At this point in the season, regardless of conditions, there’s little reason to rush to the river. Let the day develop, and concentrate your efforts during the warmer afternoon hours.

GARDNER RIVER

Speaking of taking advantage of some of the last good terrestrial days, the Gardner River is a great option this week for a single hopper or hopper-dropper rig. The rough-and-tumble pocket water of the lower river provides plenty of opportunities to prospect with a dry fly, especially during the warmer afternoon hours. 

Brown trout are also starting to filter into the river from the Yellowstone, adding another dimension to the fishing as we move toward October. It’s still early in the fall migration, but these fish will become important in the weeks ahead. Nymphing the deeper runs and pools or working a small streamer through likely holding water can be a good change of pace when fish aren’t looking up.