How to Keep Catching Fish During Spring Runoff Floods

I consistently catch my biggest trout of the year at the time when most other anglers think all the rivers are unfishable due to spring snowmelt. There’s a common misconception that fish can’t see when the water is off color. Well, I’m going to let all you MeatEater readers in on a little secret: our piscine friends don’t starve through May and June. Many popular gamefish like trout, smallmouth, and walleye consume the most calories of the year during this time. It’s certainly harder to get them to notice your offering when the rivers are pumping chocolate milk, but you can take advantage of the fact that floods will push your quarry into predictable places, they’ll be hungry, and few other anglers will be after them.

Eating from a Firehose
Most of the biggest aquatic insect hatches of the year—by volume and individual bug size—occur near or during spring high water. Mother’s Day caddis. Golden stoneflies. Green drakes. Hex. And, of course, the biggest of them all—the giant salmonfly.

Don’t think for a second that fish are unaware of this bounty. They’ll be chowing down on migrating nymphs before the hatch and slurping down adults until they’re gone. Runoff also carries all manner of fish food from flooded headwaters, lakes, ponds, and fields—from leeches, to baitfish, to frogs—even mice. Opportunistic fish gladly consume whatever the river brings.

Many smallmouth bass and walleye enter rivers to spawn in April and May, so you can intercept them when they’re pre-spawn aggressive or post-spawn hungry. Both, if you time it right. The same goes for rainbow and cutthroat trout. Fish that may be inaccessible the rest of the year can often be found in small water with the feedbag strapped on.

What Water?
If you’re fishing the same pieces of water during flood stage as you would later in the summer, you’re probably doing it wrong. Those nice, deep, outside bends where fish normally hold are likely cranking way too fast right now. Instead, look for the frog water, the stuff that normally wouldn’t have enough current to satisfy river dwelling fish. What we call muddy water is really just a higher than normal amount of sediment suspended in the water. A lot of that sediment will sink and settle out wherever the flow slows down, like side channels, slow eddies, and sloughs. Not only will those places have better clarity, but the slower water makes it a lot easier for fish to hold away from the rushing current.

My prime targets when reading maps to find fishing spots during runoff are streams below lakes or reservoirs. Still water allows sediment to settle out, and it will flow out much cleaner. Here in Montana, many of the great tailwater fisheries like the Madison, Missouri, and Bighorn rarely ever become completely unfishable. Everyone here knows that, but fewer are aware that the same tailwater effect holds true even on small creeks that flow into beaver dam impoundments and small irrigation ponds.

I also look for small tributaries flowing into mainstem rivers, especially spring-fed creeks. If you can find just the slightest sliver of clear water at the fringe of the muddy flood, fish will often be stacked in it like cord wood. If those creeks are open, you can also find fish traveling far up them in search of food and shelter from the flood. The higher you go in a basin, the clearer the water will typically be.

Positive Vibrations
Kelly Galloup, the maniac behind the big trout streamer craze, just laughs when he hears people talk about rivers being “too muddy.”

“The people that don’t fish dirty water missing out,” Galloup told MeatEater. “They [trout] don’t need to see.”

Fishes’ lateral lines are incredibly sensitive organs. They detect disturbances on the surface and vibrations within the water so well that a few species have evolved away from even having eyes. Those senses come into play for angling to a larger degree when the water is murky. Spinners that thump, streamers that push water, fluffy dry flies that slap down and skitter are a few great ways to ring the dinner bell.

There is a point of muddiness, of course, where fishing success diminishes, especially when flies are involved. If you see less than a foot of visibility you may want to keep looking. Conventional tackle, however, can produce much more vibration. During runoff on rivers I often reach for lures like Rapala stickbaits, Blue Fox Vibrax spinners, Lil Cleo spoons, and paddletail swimbaits for maximum disturbance. Anything with a lip, blade, or rattle can get the job done too.

Go Big, then Go Home
In fast, turbid water, flies and lures with big profiles will be easier for fish to notice. So, you can leave the zebra midges at home and drift the 2-inch-long girdlebug or huge wire worm instead. Skip the unweighted Zonker and throw the articulated Sex Dungeon. Forget about drifting little jigs, go rip through there with a big jerkbait.

Dark colors like black, purple, and brown contrast better against dark water and will show up a lot better as well. By the same token, flashabou and silver-plated blades reflect a lot of light and can really call ‘em in. Whatever you do, do it big and do it flashy.

Big lures and flies also often have the added benefit of being heavier and sinking faster, which is important when the water is moving quickly. Many would-be flood fly fishermen miss a lot of fish by not adding enough split-shot to their nymph rig or fishing streamers without a sink-tip. Likewise, spin fishermen throwing little Panther Martins at flood stage may struggle to get their offering in the fishes’ faces. This is the time to break out the big guns, not only to get in the zone but also because really big fish may be lurking and hungry.

You’re not going to have any fun just flogging away at any old muddy water, but if you’re willing to explore you can often find yourself a damn good time right now. But above all, you need to straight up ignore the old timers who say you can’t catch ’em during spring runoff. Persistence and creativity catch fish, not conventional wisdom.