Perhaps one of the most well known and widely used trout fly patterns. The elkhair caddis is a great fly to own in a few sizes and colors. Caddis are a species of fly found in every state in the US and they hatch often. You will see caddis fly hatches nearly every day in the spring, summer and fall. Don’t get caught on the river during an epic hatch without at least a couple elk hair caddis in your fly box.