Western March Brown Hatch

Fly Fishing During the March Brown Hatch on Rock Creek

The March Brown hatch in Western Montana is the area’s first large Mayfly hatch of the season. Inappropriately named, the March Brown hatch actually occurs in mid to late April in the Missoula Area.

Choosing a Fly

There are numerous patterns out there to imitate the bugs but we tie a pattern that consists of a dubbed body with gray/brown/hint of purple dubbing, micro-fribbit tail (3), and a segmented body (just thread will do). This all ties on a size 14 dry fly hook. The wing is 3 dun CDC feathers fashioned on the shaft – think CDC Caddis. And that’s it!

When you watch the video, you’ll see trout looking up at the surface of the water hunting for bugs. Having your fly match the underside of a bug is more important than the top. So with dry flies, make them floatable, make them easy to see, and match that underside!

Timing the Hatch

The March Brown hatch comes off between 1-2 pm and lasts for about two hours. I like to be on the water a little ahead of the hatch, say 11 or noon. Trout are waiting for the hatch but will feed on nymphs and emergers as the hatch approaches.

The birds are the best indication that the hatch is beginning. Out of nowhere, here they come scooping up bugs near the surface of the water.

Using a Dry Fly During the Hatch

While some duns (adult mayflies) may wash to the edges of the river, keep a keen eye on the riffles and feeding lanes. Rises are harder to spot in the broken water but that’s exactly where the fish are watching and feeding.

Feeding lanes or feeding lines are nothing more than a bubble line or foam line. If a leaf fell in the water and it was carried into the current, that’s your feeding lane. Bugs swept into the current end up in the lanes.

As the hatch progresses, larger fish will cruise into the soft edge plucking off bugs. They don’t hold in one place long as they are on the hunt but they do make their “rounds”.

Have fun, stay dry, and share your photos on our Facebook group page Fly Fishing Travels.