In April, Don’t Forget About March Browns!

For the dry fly angler on the Yellowstone River this time of year, the focus is on midges and baetis mayflies (blue-winged olive) mayflies, the little stuff. But if you’re hitting the river from now until runoff, you should be prepared for an emergence of the larger Western March Brown mayflies. If you start seeing big “sailboats,” you’re in for a treat! When the fish are coming out of their winter doldrums and see a bug of that size, they’ll be eating with abandon. Throw a size 14 Parachute Adams and you’ll probably pick up some fish, but I prefer a fly with a darkish brown body, such as a Copper Haze, to better match the naturals. Imitating the nymph with a #14 pheasant tail or similar isn’t a bad idea this time of year as well. The March Brown emergence is spotty in the Paradise Valley, but keep your eyes open. I’ve most often seen them emerging at the mouths of tributaries as they enter the Yellowstone. If you happen to come upon these chunky bugs, you’re guaranteed to get some early season dry fly action!