By the end of the 1700's the Holland Land Company was operating in western New York, including Chautauqua County, and the first permanent European settlers arrived soon after; by 1811 the county's population surpassed 500 European inhabitants. Limited information exists regarding the early occupants of this area, but indications of the culture known as the "Mound Builder" have been found, followed by evidence of Erie Indian occupation, and the Seneca were the next occupants dominating the area; their descendants, many still living in Chautauqua County, maintain four reservations in western New York. Chautauqua Lake sits 700 feet higher than Lake Erie although only six miles away, with Lake Erie's waters draining into the Atlantic Ocean while Chautauqua Lake's waters drain into the Gulf of Mexico. In the 1740's French explorers landed in Chautauqua County on the shore of Lake Erie seeking a southward passage to the Ohio and Mississippi Rivers, and the route connecting Barcelona Harbor on Lake Erie with Chautauqua Lake, later known as the Portage Trail, offered the answer.