On November 5, 1768, the British acquired land, known in Pennsylvania as the New Purchase, from the Iroquois in the Treaty of Fort Stanwix; this included what is now Ganoga Lake. After the American Revolutionary War (1775-1783), Native Americans almost entirely left Pennsylvania. The lake was originally in Northumberland County, then became part of Lycoming County when it was formed in 1795. Sullivan County was formed from Lycoming County in 1847, and two years later Colley Township was formed from Cherry Township. The lake drains into Kitchen Creek, where a Native American pot, decorated in the style of the peoples of the Susquehanna region, was found under a rock ledge around 1890.