Well, I wasn't going to call it P. dorsata, but since the atlas does, I'll assume that the other species that I thought was a possibility is not living up here.
Resting on railing behind my office, Amherst MA
In its larval state
Observed in seasonal pond. Forked (2) tails, fairly short, no antennae observed. 6 legs.
Looks like this one: http://bugguide.net/node/view/245023
Plecoptera are an order of insects, commonly known as stoneflies. There are some 1,700 recorded species worldwide, and new ones are still being discovered. Stoneflies are believed to be one of the most primitive groups of Neoptera, with close relatives identified from the Carboniferous and Lower Permian geological periods, while true stoneflies are known from fossils only a bit younger. The modern diversity however apparently is of Mesozoic origin.