Lake Itasca is a small glacial lake, approximately 1.8 square miles (4.7 km²) in area, in the Lake District of northwestern Minnesota in the United States. It is the source of the Mississippi River. The lake is located in southeastern Clearwater County within Itasca State Park. It has an average depth of 20-35 feet (6-11 m), and is 1,475 ft (450 m) above sea level.