Term: Door county [origin of place name]
Door County took its name from the straits between the mainland and Washington Island, locally known as Death's Door, a translation from the French voyageur term, ''La Porte des Morts" (the door of the dead). Wis. Hist. Colls., vi, p. 166. The origin of this name is traditional, probably having arisen from the dangerous character of these waters. Hist. No. Wis., p. 253.
Description from John W. Hunt's 1853 Wisconsin Gazetteer: "DOOR, County, is located between Green Bay and Lake Michigan, and is bounded on the north and east by the State line of Michigan, on the south by Kewaunee, and on the west by Oconto. It was set off from Brown, February 11, 1851. It then included the present county of Kewaunee, and was attached to Manlitowoc for judicial government. The county seat was established at Gibralter, on Gibralter Bay, heretofore known as Bailey's Harbor, on the west shore of Lake Michigan, in town 30 N., of range 28 E. Door county is for legislative and county purposes, in connection with Brown county. It has several small streams emptying into the Bay and into Lake Superior."
[Source: Kellogg, Louise Phelps. "Derivation of County Names" in Proceedings of the State Historical Society of Wisconsin for 1909, pages 219-231.]