Keene is a town in central Essex County, New York, United States. The population was 1,063 at the 2000 census. Keene is the home of Mount Marcy, the highest mountain in New York state, as well as the Great Range and 15 of the 46 High Peaks, and the Ausable Lakes, the source of the Ausable River. Trailheads for many of the High Peaks are located within the town, along with the Johns Brook Lodge of the Adirondack Mountain Club. All of the town is in the Adirondack Park, the largest state park in the nation.