I took the kids up to Pine Haven again for a single overnight last night, and had some excellent insect-related adventures. I'd found a dead polyphemus moth last year, and hestitated a little at posting pictures. This time, I got to see a live one - it had apparently been sitting on the office door at the campsite all day.
I've included a picture showing most of the door for scale; the moth is about as big as my hand. Polyphemus moth (Antheraea polyphemus), Wentworth NH, 6/13/2015.