Of all of Iowa's drainage features a seemingly unique phase is the gorge of the upper Des Moines River, on that stretch of stream above the Capital City. As is well known, this part of the Valley is a deep, V-shaped gorge gashed in the upland prairie, a canyon, in fact, with short lateral canyons instead of the normally long, widely dendritic tributaries. This gorge has bed-rock walls and bed-rock bottom, attesting its extreme recency of formation. In these respects it contrasts strongly with the valley of the lower Des Moines River, between Des Moines city and the mouth of the stream at Keokuk, which is a wide, flat-bottomed trench, with old bed-rock channel 150 feet below the level of the present floodplain.
Proceedings of the Iowa Academy of Science
©1937 Iowa Academy of Science, Inc.
Keyes, Charles R.
"Recency of Origin of Upper Des Moines River,"
Proceedings of the Iowa Academy of Science, 44(1), 131-131.
Available at: https://scholarworks.uni.edu/pias/vol44/iss1/32