Passamaquoddy Bay is an inlet of the Bay of Fundy, between the U.S. state of Maine and the Canadian province of New Brunswick, at the mouth of the St. Croix River. Most of the bay lies within Canada, with its western shore bounded by Washington County, Maine. The southernmost point is formed by West Quoddy Head on the U.S. mainland in Lubec, Maine; and runs northeasterly through Campobello Island, New Brunswick, engulfing Deer Island, New Brunswick, to the New Brunswick mainland head at L'Etete, New Brunswick in C******te County, New Brunswick.