“National Registry of Natural Landmarks”

Minnesota – Dakota

Lake Agassiz was created when the south moving glaciers blocked the flow of the RED RIVER of the North until the glacier receded. Water spilled out of this lake and cut a channel of 50 to 90 feet below the present channel of the Minnesota River. The River Warren, a geological phenomenon, was named for Lt. Governor K. Warren, whose western topographic maps are justly famous. He was later a Union General in the Civil War and was the first District Engineer at St. Paul in 1866. As the glacier receded and Lake Agassiz dried up, the River Warren became less potent, sediment was deposited and the channel became as we see it today. The present channel is about two miles wide and from 100 to 130 feet in depth. Lake Traverse, flowing to Hudson’s Bay, is nine feet above Big Stone Lake. Between them is the Continental Divide between the Gulf of Mexico and Hudson’s Bay. You are viewing one of the geological indexes to ancient history. Another glacier, moving west and south, created the Missouri River and deflected the former channel of the Cheyenne River, as a tributary of the Red River of the North into the Missouri Channel.

Burial Mounds

Eastern South Dakota has a good many Burial Mounds, located in this roadside park and in Roberts County and elsewhere in the Big Sioux and James River Valleys. Well known Mounds are located west of Faulkton; in the Southside Park at Mitchell; near the mouth of 12 Mile Creek near Milltown; and at Sioux Falls; and nearby Brandon. It is believed they were created by basket-carried earth.

Artifacts recovered included pottery, stone, knives, and hammers and both marine and fresh water shell beads. The Mounds are ordinarily on high terraces overlooking water courses. The

human burials appear to be both original in the site and secondary, that is, by other burials elsewhere brought to the site. It is speculated that they may have had other purposes as fortifications and perhaps religious significances. They are monuments to labor. Comparable to the creation of an ant heap and to the culture of an ancient race in the history of this Continent. The Mound in this Park is typical, as are the others in South Dakota, of an existing culture between 300 and 1400 A.D.

Roberts County, SD 10 10 mi E & S of Sisseton over Lake Traverse (1988)