The Ice Age National Scientific Reserve is an affiliated area of the National Park System of the United States comprising nine sites in Wisconsin that preserve geological evidence of glaciation. To protect the scientific and scenic value of the landforms, the U.S. Congress authorized the creation of a cooperative reserve in 1964. The scientific reserve was established in 1971 and today encompasses some 32,500 acres (13,200 ha). The landforms are the result of the Wisconsin glaciation during the last glacial period, which lasted from about 110,000 to 10,000 years ago.