A strath terrace, known as the Chengwatana surface provides evidence for the occurrence of the first drainage event. The Chengwatana surface is a scoured surface marked by distinct lemniscate landforms; bar-shaped lndforms composed of sand; and a lag layer of cobbles and boulders. This lag layer overlies an unconformity eroded into older glacial till, lake sediment, or bedrock. This surface extends from the lower reaches of the Kettle River valley as far south as Sunrise, Minnesota. The Chengwatana surface likely was cut by water flowing down the Kettle River from the Moose Lake outlet of glacial Lake Nemadji and the Epi-Duluth level of glacial Lake Duluth. The association of the Chengwatana surface with glacial Lake Nemadji and the Epi-Duluth level of glacial Lake Duluth would make it most likely range in age from before 12,100 to about 11,700 BP calibrated.