Aerial photograph showing flooding in the Traverse Gap, the former southern outlet of Glacial Lake Agassiz and the source of River Warren. Ice-covered Lake Traverse (Mde Hdakiŋyaŋ), a natural border between Minnesota (left) and South Dakota (right) is at bottom center; Big Stone Lake (Mde Iŋyaŋ Taŋka) is at top center. Photo by JOR Engineering, Inc., March 14, 2007. CC BY-SA 3.0