The Grasse River or Grass River (per 1905 decision of the U.S. Board on Geographic Names) is a river in northern New York, in the United States. The river mainly flows northeast from the foothills of the Adirondack Mountains into the St. Lawrence Valley, making up what is known as the greater St. Lawrence River Drainage Basin along with other tributaries such as the Oswegatchie and Raquette rivers. The river was named after François Joseph Paul, comte de Grasse, a French admiral and hero of the American Revolutionary War. He defeated British forces in the Battle of the Chesapeake, contributing to their surrender at Yorktown, ending the war. The source The river is created by a series of small ponds, lakes and streams located in the northern New York towns of Russell, Clare and Clifton. Two main branches of streams and ponds, known as the Northern Branch and Southern Branch, lay claim as the ultimate source. The southern branch is the dominant flow of the river, feeding off Moosehead Pond and Little Moosehead Pond, and is located near the hamlet of Degrasse. The weaker northern branch is fed from smaller ponds such as Clear Pond, Bullhead Pond and Horseshoe Pond near the hamlet of Russell, and runs through the Grasse River Wild Forest Reserve. The two branches meet in the town of Russell and form the main branch of the river, which slowly grows along its northeasterly track. This area of New York was first explored in the 1790s as part of the Macomb's Purchase, in which Alexander Macomb, a wealthy Revolutionary-Era American merchant purchased 3.6 million acres (15,000 km²) from New York State at 12 cents an acre. This area was divided into counties and townships which were established between 1800 and 1815. The area thrived on thick pine forests, stone quarries and the mining of various ores. On the St. Lawrence Valley floor, the pine forests were razed and the land used for agriculture, and later for industry. Course The Grasse River, along with the other tributaries to the St. Lawrence River, served as a water power source for several mills in the towns and hamlets along its course. Almost none of these mills has survived, but stone foundations, burned out furnaces, and other ancient structures can be located along its banks. Several Old World dams exist along the path of the Grasse River. Its so-called "twin" sister