Lake Sherburne Dam - Credit: Wikimedia Commons
Lake Sherburne Dam is a high compacted earthfill dam built between 1914 and 1921, just outside the boundary of Glacier National Park, Montana, its reservoir extending into the park. The dam impounds Swiftcurrent Creek as it flows out of the park. Water stored in Lake Sherburne is released to flow down Swiftcurrent Creek to the St. Mary River, from which it is diverted to the Milk River, flowing through Canada for before returning to the United States. Use of these waters is governed by the Boundary Waters Treaty of 1909. Water from the Milk River is used for irrigation in north central Montana. Read more on Wikipedia
Source: en.wikipedia.org