The Moose River is a beautiful pristine mountain waterway which consists of three branches: the North Branch, the Middle Branch and the South Branch. The outlet of Big Moose Lake forms the North Branch in northern Herkimer County. The Middle Branch originates at the Fulton Chain Lakes in Old Forge. And the Southern Branch has its headwaters in Little Moose Lake in Hamilton County. It flows generally westwardly through Herkimer County into Lewis County, reaching its confluence with the Black River in Lyons Falls.