York County is the most southwestern county of the state of Maine located along New Hampshire’s eastern border in the United States. It is divided from Strafford County, New Hampshire by the Salmon Falls River, and the connected tidal estuary—the Piscataqua River. Permanently re-founded in 1639, it held several of the oldest colonial settlement in Maine; consequently, is the oldest county in Maine and one of the oldest in the United States. As of the 2010 census, the population was 197,131, making it the second-most populous county in Maine. Its county seat is Alfred. York County is part of the Portland–South Portland, ME Metropolitan Statistical Area.