Most of what makes the Pennsylvania Green Drake hatch difficult has nothing to do with the hatch itself. The insect is large, obvious, and highly imitable at sizes 8 to 10. The water is well-documented and has been since the 1920s. What’s difficult is that the window at any given bend of river usually lasts about seven to ten days, moves upstream at a pace the weather determines, and concentrates the heaviest surface feeding in the last hour of daylight and the hour after it. That’s a band of time short enough that many trips end up planning for the wrong part of it.

The single most-repeated mistake during drake week isn’t fly choice. It’s treating the hatch as a calendar event rather than a reach event.