Fly Fishing During Spring Runoff in Montana: Tips for Tackling Big, Dirty Water
What is Runoff?
Spring in Montana is a paradox for fly fishers. On one hand, the weather is warming, hatches are stirring, and trout are hungry after a long winter. On the other hand? Snowmelt hits the rivers like a freight train. High, muddy flows make rivers look more like chocolate milk than prime trout habitat. But don't hang up your waders just yet.
With the right strategies, you can fly fish during runoff—and sometimes, it’s even better than you’d expect.
1. Fish the Edges, Not the Middle
When the river is blown out, the main current is often too strong for fish to hold comfortably. Instead of casting into the middle, focus on the soft water along the banks, back eddies, and inside bends. These areas offer trout shelter from the current and a steady flow of food getting flushed downriver.
Look for:
Slow seams next to fast water
Back eddies behind rocks or logs
Flooded side channels or sloughs
2. Go Big, Dark, and Flashy
Dirty water means low visibility. To help fish find your fly, go with bigger patterns that create a strong silhouette. Dark colors (black, brown, olive) stand out best, and a little flash doesn’t hurt.
Top fly choices include:
Woolly Buggers (black or olive, size 4–8)
Rubber Legs / Big Stoneflies
Zonkers or other streamer patterns
San Juan Worms or Squirmy Wormies
Big nymphs with some flash
Don’t be afraid to throw streamers either—especially when water temps are climbing and trout are aggressive.
3. Use Heavy Tippet and Weight
In runoff conditions, you’re not fooling picky trout in clear water. You’re trying to get their attention and get down fast. Use heavier tippet (3x or 2x) to turn over big flies and manage strong currents. You’ll also want plenty of weight—either in your flies, split shot, or sinking leaders—to get your rig down where fish are holding.
4. Try Stillwaters and Tailwaters
If rivers are completely unfishable, consider changing your venue. Spring runoff is a great time to hit:
Lakes and reservoirs – Ice-off is prime time for hungry trout cruising the shallows.
Tailwaters – These rivers below dams often have more stable flows and clearer water.
Spring creeks – Fed by groundwater, these systems stay clearer than freestone rivers.
Some of our local reliable spring options include the Missouri River, the Madison River, or spring creeks near Livingston and Ennis.
5. Safety First
Runoff season isn’t the time to test your wading skills, rowing skills or sketchy crossings. Fast, high water can be dangerous. Always wear a wading belt, use a wading staff, and don’t wade deeper than you're comfortable. If you aren’t an experienced rower, its not the time to be floating, debris in the water and heavy currents make floating very dangerous. When in doubt, fish from the bank—you’ll often do just as well.
Final Thoughts
Spring runoff might not offer picture-perfect river days, but it’s still a solid window to chase trout in Montana. With the right flies, smart reading of the water, and some creativity, you can turn a blown-out river into an unexpected success.
Don’t pack away the fly rods—just adjust your tactics. The fish are still there, and they’re still hungry.
