I lifted a rock in pursuit of a stonefly nymph that had scurried beneath it, and instead I found this Ephemera simulans burrowing mayfly nymph waiting to be photographed.
In this picture: Mayfly Species Ephemera simulans (Brown Drake).
Troutnut.com is a collection of pictures and information about fly fishing. Fly fishermen, fly tiers, and trout enthusiasts of all stripes can learn more about life beneath the surface of trout streams, as well as how to better imitate aquatic insects with artificial flies to catch trout. There are aquatic insect pictures, underwater pictures, landscape pictures, and a comprehensive reference to the common names of trout stream insects.