The Adirondack Mountains form a massif in northeastern New York state, which is part of the United States. Its boundaries roughly correspond to those of the Adirondack Park. They cover about 5,000 square miles (13,000 square kilometers). The mountains form a roughly circular dome, about 160 miles (260 km) in diameter and about 1 mile (1,600 m) high. The current relief owes to the glaciation. There are more than 200 lakes around the mountains, including Lake George, Lake Placid, and Lake Clouds, which is the source of the Hudson River. The Adirondack region is also home to hundreds of mountain peaks, some of which reach heights of 5,000 feet (1,500 m) or more.