There's a lot more than just the altitude that makes high mountain lakes different than Midwest farm ponds. Not many of them hold schools of bluegill being stocked by bass and the occasional blue cat. Maybe there are, but nobody knows because all they do is fish for trout. That'd be pretty funny. Anyways, whether its bluegill in farm ponds or trout in alpine lakes they both love damsel flies. With spring on its way now's the time to stock your box with this simple and effective imitation.