Southwest Montana Fly Fishing Report | Spring Conditions & Best Rivers Now
Dillon Public Slough
Southwest Montana Fishing Report
Warm Temps, Early Spring Vibes & Consistent Action Across the Board
Spring has shown up early in Southwest Montana this year, and the fishing is reflecting it. With warmer-than-average temperatures and a relatively mild winter, we’re seeing conditions that feel more like mid May. Water temps are creeping up, bug activity is increasing, and trout are feeding more consistently than usual for this time of year.
Across the region, stable flows and mild weather have kept fish active, with nymphing leading the charge and windows of dry fly and streamer action improving daily.
Beaverhead River
The Beaverhead is doing what it always does this time of year—producing heavy Browns. The flows are still LOW 36cfs out of the dam and 100 cfs at Barretts floating is not an option.
Expect classic tailwater fishing:
Go-to rig: Sowbugs, scuds, Baetis, zebra midges (#18–20)
Add weight: Fish are still hugging the bottom
Best time: Late morning into afternoon when temps bump up
With the early spring conditions, don’t be surprised to see the occasional BWO hatch bringing a few fish to the surface, but subsurface is still king.
Big Hole River
The Big Hole is waking up quickly this year.
Flows have seen some fluctuation recently, but overall conditions are improving as temps rise. Fish are transitioning out of winter lies and starting to spread into more classic holding water.
Nymphing remains best: Rubberlegs, worms, and small baetis patterns
Streamer bite: Picking up on warmer, overcast days Yellow
Dry fly potential: Keep an eye out for early Skwala action
As flows stabilize, expect this river to really turn on. This is shaping up to be a strong pre-runoff window, especially with less pressure and eager fish.
Big Hole River Brown Trout
Madison River
The Madison continues to be one of the most consistent options in the region.
Thanks to the mild winter, trout have stayed active and are feeding regularly. Conditions are stable, and the river is fishing well from top to bottom.
Nymphing: Zebra midges, baetis nymphs, small stones
Dry fly windows: Midges on calm afternoons
Streamer fishing: Improving with warmer weather trends
Fish are holding in classic winter-to-spring transition water—inside seams, slower runs, and soft edges. If temps keep climbing, expect more consistent dry fly opportunities soon.
Missouri River (Holter Dam to Cascade)
The Missouri below Holter is fishing exactly how you’d expect in an early, warm spring—steady and productive.
Mild temps have carried over from winter, keeping fish active and predictable.
Main game: Nymphing with midge patterns
Dry fly shots: Afternoon midge hatches, especially on calm days
Streamer bite: Very solid pre-runoff opportunity
Low snowpack and warming trends could mean lower flows and slightly warmer water temps heading into spring, which can actually concentrate fish and improve consistency in the short term.
Focus on slower seams and buckets where fish are stacked up and feeding.
Final Outlook
This is one of those “don’t miss it” windows in Southwest Montana.
Warmer-than-average temps
Active fish across all major systems
Minimal pressure before peak season
If conditions hold, we’re looking at an exceptional early season with strong nymphing, improving streamer action, and the first real dry fly opportunities of the year.
Game plan:
Sleep in, fish late, focus on good water, and don’t overlook the afternoons.
