Here’s Walter’s latest fly tying video, the CDC Emerging Dun. This gray version is my most productive fly when guiding in the Lamar Drainage. It’s an excellent imitation of emerging Green Drakes (as well as a variety of smaller gray-olive “drake” mayflies). You can also tie it much smaller to match BWO, or change colors to match whatever insect you are seeing.
The video is below. The recipe is available at Yellowstone Country Fly Fishing.