The common porcupine can be found in most of Canada and the western United States south to Mexico. In the eastern United States, it can be found in Wisconsin, Michigan, Pennsylvania, New York and New England.
www.nhptv.org

I'msure that I've seen porcupine in CT. The first one was up in a tree about thirty yards away and the second one walked directly beneath my stand so Ihad plenty of timeto watch it. It's quills were long and yellow and its body was black.