The Minnesota River Valley
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The Minnesota River is a tributary of the Mississippi River, approximately 332 miles (534 km) long, in the U.S. state of Minnesota. It drains a watershed of nearly 17,000 square miles (44,000 km²), 14,751 square miles (38,205 km²) in Minnesota and about 2,000 sq mi (5180 km²) in South Dakota and Iowa.
It rises in southwestern Minnesota, in Big Stone Lake on the Minnesota–South Dakota border just south of the Laurentian Divide at the Traverse Gap portage. It flows southeast to Mankato, then turns northeast. It joins the Mississippi south of the Twin Cities of Minneapolis and St. Paul, near the historic Fort Snelling. The valley is one of several distinct regions of Minnesota. As shown on old maps of Fort Snelling, early explorers dubbed the waterway the St. Pierre or St. Peter's River. Pierre-Charles Le Sueur was the first European to visit the river, but there is no consensus as to the origin of its original name.
Its name comes from the Lakota language mini meaning "water" and sota which is alternately translated "smoky-white" or "like the cloudy sky". Minnesota Territory, and later the state, were named for the river.
The valley that the Minnesota River flows in is up to five miles (8 km) wide and 250 feet (80 m) deep. It was carved into the landscape by the massive glacial River Warren between 11,700 and 9,400 years ago at the end of the last ice age in North America.
While active this turbulent stream cut and eroded a bed up to five miles (8 km) wide and 250 feet (80 m) deep. This has left a valley which starts at Traverse Gap near Browns Valley, Minnesota, goes southeast to Mankato, then turns northeast to the Twin Cities. River Warren was joined by the comparatively small Mississippi at Fort Snelling, from which the valley continues northeast to present-day Saint Paul, where the massive River Warren Falls once graced the landscape. Over 1700 years this waterfall retreated upstream and undercut the Mississippi at the site of Fort Snelling. The falls then split. The Mississippi falls migrated upstream to form Saint Anthony Falls and create Minnehaha Falls in Minneapolis. The River Warren falls receded west in the Minnesota River valley until they reached an older buried river valley about two miles (3 km) west of the confluence, where the falls were extinguished.
From Saint Paul the great valley goes southeast to Prescott, Wisconsin, where it is joined by the St. Croix River, itself once the outlet of another proglacial lake, Glacial Lake Duluth which occupied the western part of Lake Superior. From its confluence with the St. Croix the valley continues southeast along the Minnesota-Wisconsin border. River Warren's effects include the creation of bluffs along the valleys of the Minnesota and Mississippi Rivers, and contributed to the formation of Lake Pepin.
By about 9400 BP, the ice sheet finally retreated sufficiently far to the north that Lake Agassiz permanently took another outlet and receded below the level of Traverse Gap. River Warren then ceased to run. The Lake Agassiz area watershed now feeds the Red River of the North which flows north, ultimately to Hudson Bay. River Warren's upper valley in the Traverse Gap is now occupied by the tiny Little Minnesota River, which flows into Big Stone Lake and the Minnesota River, which follows the greater river's ancient bed to its confluence with the Mississippi River. These streams occupy only a small cross-section of River Warren's riverbed.
(The hydrology of the oversized valley was first explained by General G. K. Warren in 1868. He made a detailed survey of the valley in his search for possible transcontinental railroad routes. Posthumously, in appreciation of this work, the glacial river that was the outlet of Lake Agassiz was named River Warren.)
The river valley is notable as the origin and center of the canning industry in Minnesota. In 1903 Carson Nesbit Cosgrove, an entrepreneur in Le Sueur presided at the organizational meeting of the Minnesota Valley Canning Company (later renamed Green Giant). By 1930, the Minnesota River valley had emerged as one of the country's largest producers of sweet corn. Green Giant had five canneries in Minnesota in addition to the original facility in Le Sueur. Cosgrove's son, Edward, and grandson, Robert also served as heads of the company over the ensuing decades before the company was swallowed by General Mills. Several docks for barges exist along the river. Dried goods are transported to the ports of Minneapolis and Saint Paul, and then shipped down the Mississippi River.
Approximately how old is the Minnesota River?
Which ancient river channel does it flow through?
How long is the Minnesota River?
From this location as a bird flies how far is it to the headwaters?
N 45° 17.832 W 096° 26.874
What geological evidence do you see around you that form the deeper, ancient channel?
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