Fishing Report - 9/18/2026
Montana
Flows/Temperatures (as of September 17th; click the name for real-time numbers)
Hebgen Outflow - 759.9 CFS
Kirby - 864 CFS
Kirby High/Low Temps - 62°/53°F
Cameron - 926 CFS
Cameron High/Low Temps - 60°/54° F
This Week's Weather Forecast in the Valley
Upper Madison
Fall is settling into the valley in truth now. We've got some rain rolling through this weekend, and with temps below freezing most nights, the Madison is falling into its usual late-season patterns. Fishing is a bit slow to start up in the mornings, with the bite turning on around 10-11 am in my experience, and getting better as the air warms up.
The dry fly bite has slowed but is by no means done, with the periodic BWO hatches and caddis bringing eager rises in the slicks and along the banks. Hoppers can still bring a fish up as well, but from my experience, fish are much more tentative to rise on foam than they have been in weeks past. Nymphing is the most productive method (as usual, I know), with smaller mayfly emergers and general attractors being the ticket if fishing is slower. As this rain continues, streamers/swung flies will gain traction and attract those fish eager to eat before the true cold arrives!
Dry Flies - Winna Spinna, Ant Acid, Arricks Flying Ant, Parachute Adams
Nymphs - Olive Hot Spot, Sunburst Perdigon, BBQ Baetis, Red Neck
Hebgen Outflow - 759.9 CFS
Kirby - 864 CFS
Kirby High/Low Temps - 62°/53°F
Cameron - 926 CFS
Cameron High/Low Temps - 60°/54° F
This Week's Weather Forecast in the Valley
Upper Madison
Fall is settling into the valley in truth now. We've got some rain rolling through this weekend, and with temps below freezing most nights, the Madison is falling into its usual late-season patterns. Fishing is a bit slow to start up in the mornings, with the bite turning on around 10-11 am in my experience, and getting better as the air warms up.
The dry fly bite has slowed but is by no means done, with the periodic BWO hatches and caddis bringing eager rises in the slicks and along the banks. Hoppers can still bring a fish up as well, but from my experience, fish are much more tentative to rise on foam than they have been in weeks past. Nymphing is the most productive method (as usual, I know), with smaller mayfly emergers and general attractors being the ticket if fishing is slower. As this rain continues, streamers/swung flies will gain traction and attract those fish eager to eat before the true cold arrives!
Dry Flies - Winna Spinna, Ant Acid, Arricks Flying Ant, Parachute Adams
Nymphs - Olive Hot Spot, Sunburst Perdigon, BBQ Baetis, Red Neck
Hebgen/Quake Lake
The dry fly fishing on the lakes has slowed down as this cold front settles in, but they can still be found in the arms from time to time. As these cold nights and mild days continue, the transition into stripping streamers or nymphs begins.
As of 9/11; The edges of weed mats are still the most productive places to target fish if you're throwing drys, and the deeper stretches between them are a great spot to strip a bugger through. If you are throwing streamers, I'd recommend having them on a longer leader (~9 ft) as that's been working best for me!
Quake is fishing similarly, although risers are a bit more spaced out and keyed into spruce moths as well!
Dry Flies - Parawulff Adams, Nyman's Flying Ant, Long-Tailed Spinner Callibaetis
Nymphs - Turkey Callibaetis, Ice Cream Cone, Pheasant Tail
Streamers - Hot Bead Leech, Simi-seal Leech, Montana Mouthwash
The dry fly fishing on the lakes has slowed down as this cold front settles in, but they can still be found in the arms from time to time. As these cold nights and mild days continue, the transition into stripping streamers or nymphs begins.
As of 9/11; The edges of weed mats are still the most productive places to target fish if you're throwing drys, and the deeper stretches between them are a great spot to strip a bugger through. If you are throwing streamers, I'd recommend having them on a longer leader (~9 ft) as that's been working best for me!
Quake is fishing similarly, although risers are a bit more spaced out and keyed into spruce moths as well!
Dry Flies - Parawulff Adams, Nyman's Flying Ant, Long-Tailed Spinner Callibaetis
Nymphs - Turkey Callibaetis, Ice Cream Cone, Pheasant Tail
Streamers - Hot Bead Leech, Simi-seal Leech, Montana Mouthwash
Yellowstone National Park
Madison, Firehole, Gibbon - If you are one of those eager to target lakers on their way out of Hebgen, now is the time to brush the dust off that two-hander and get out there. I went out on the Madison earlier this week and had success with softhackles (in green and orange) and streamers alike. Finding a good stretch of water all to yourself is key, so prepare to go for a little stroll away from the crowds.
Gallatin - As of 9/11; Terrestrials are still the way to go on the Gallatin. A smaller hopper or ant would do the trick, especially on the sunny afternoons. When those fish aren't looking up, a flashy nymph like a rainbow warrior has been doing well!
Northeast Corner - With this rain, the Lamar is officially blown once again. Slough and Soda Butte should be at the very least clouded up a fair bit, so I would stick to the western side of the park if you want to fish within Yellowstone. If you find yourself in the area, a small leech (or very large hopper) should be enough to entice a cutty or two.
Gallatin - As of 9/11; Terrestrials are still the way to go on the Gallatin. A smaller hopper or ant would do the trick, especially on the sunny afternoons. When those fish aren't looking up, a flashy nymph like a rainbow warrior has been doing well!
Northeast Corner - With this rain, the Lamar is officially blown once again. Slough and Soda Butte should be at the very least clouded up a fair bit, so I would stick to the western side of the park if you want to fish within Yellowstone. If you find yourself in the area, a small leech (or very large hopper) should be enough to entice a cutty or two.
See you on the river,
Nina Lett
MRO Assistant Manager & Guide
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