Date of Award
Master of Science (MS)
Bedrock river terraces, as much as 275 to 500 feet above the present Little Missouri, are remnants of a former floodplain. The presence of these former shallow valley floor (Little Missouri Terrace No. 4) along the pre-glacial channel and east and north of the Killdeer Mountains suggests several pre-glacial rivers.
Peripheral precipitation in advance of the Kansan-Illinoian glacier, head-ward erosion with consequent new gradient breached the divide between the pre-glacial Little Missouri River and the “Medicine Stone” River, (herein named, after a local landmark), which flowed eastward into pre-glacial Missouri River.
The history of that portion of the Little Missouri River that flows ninety miles eastward from “The Bend” in T. 147 N., R. 101 W., to its junction with the Missouri River near the center of T. 148 N., R. 91 W., is characterized by a succession of pirating streams with resulting local inversion of drainage. This cycle of stream capture includes five main stages that are outlined below.
Stage No. 1 – Pre-glacial Little Missouri River flowed north to Yellowstone River.
Stage No. 2 – Little Missouri River was captured by Cherry Creek.
Stage No. 3 – Cherry Creek and the Little Missouri River were captured by Medicine Stone River. This was followed by deep trenching of the newly established valley.
Stage No. 4 – This marks the beginning of continental glaciation and alluviation of the previously entrenched channel.
Stage No. 5 – Maximum glaciation was followed by re-trenching of the old-channel.
The present Little Missouri River, although intermittently overloaded, is progressively cleaning its channel in the process of establishing a new gradient.
Schmitz, Emmett R., "Stream piracy and glacial diversion of Little Missouri River, North Dakota" (1955). Theses and Dissertations. 265.