Sure, everyone is focused on the salmonflies right now, but the truth is the mayfly hatches have been unreal on the rivers in western Montana this spring, which is uncommon for the freestones that we usually fish. When the mayflies are coming off like they are, it’s time for us big bug slingers to turn to our friends on the tailwaters for some patterns that really hit the mark. When we’re talking tailwaters, there is none better than the Bighorn river. And when you’re talking shops on the Bighorn, there is none better than the Bighorn Angler. So no surprise here that their main tying guru Pete Shanafelt has a great pattern that works great during mayfly hatches. This tutorial on a Split Case PMD Nymph is simple and straightforward, and will have you churning out dozens of the pattern in no time. I like this pattern more than some other split case offerings due to the use of foam and boots for the emerging wings, which tend to give the fly a bit of bouyancy and a gloss to the wing case that more accurately mimics the naturals. Other patterns use epoxy and paint to get the same effect, and I tend to stay away from materials that have long drying times or tricky techniques as much as possible. Though paint and epoxy have their places in fly tying, I sometimes need a fly to be ready in five minutes so that I can hit the water, and having the pile stuck together when I get to the boat is a no go for me. Try this pattern for your next mayfly-full day, or fish it underneath a smaller attractor and watch it go boom. Sure, it might be best as a Pale Morning Dun imitation, but it will get them whenever the size is right.