Peespunk appears quite a few times in very early deeds, reflecting a little-known custom practiced by the American Indians. First cited in a 1712 deed in which the proprietors granted land lying on both sides of “Peespunk Spring”; eventually, deeds simply referred to land “at Peespunk.” The word, from “pesuppau-og,” meaning “they are sweating,” appears in the languages of the Narragansett and the Paugusett tribes; the latter lived in parts of Fairfield County. A peespunk or “sweat lodge” was a hut or cave where native men built hot fires and took ceremonial sweat baths, subsequently cooling off in nearby water (the spring). Peespunk seems to have been on a West Mountain hillside on the west side of North Salem Road near the New York line.
From Jack Sanders, Ridgefield Names.