The Mississippi River Headwaters dams, located in north central Minnesota, were constructed and placed in operation between 1884 and 1912. Maj. General Warren, the first St. Paul District commander, noted the importance of the Mississippi River Headwaters area during field surveys in the 1860s. Less than 10 years later, Congress authorized a feasibility study to determine whether a series of dams and reservoirs could aid in stabilizing water flow in the Mississippi River between St. Paul, Minnesota, and Prairie du Chien, Wisconsin. As a result, a system of dams capable of raising water levels and storing annual spring runoff from six existing lake systems was designated. These structures are located at the outlets of Gull Lake, Leech Lake, Big Sandy Lake, Cross Lake, Pokegama Lake and Lake Winnibigoshish. Two of these lakes, Leech and Winnibigoshish, are located within the Leech Lake Indian Reservation.