Mount Marcy is the highest point in the U.S. state of New York, with an elevation of 5,343.1 feet. It is located in the town of Keene in Essex County. The mountain is in the heart of the High Peaks Wilderness Area in Adirondack Park. Like the surrounding Adirondack Mountains, Marcy was heavily affected by large glaciers during recent ice ages, which deposited boulders on the mountain slopes and carved valleys and depressions on the mountain.