— Great River Road Minnesota —

Twenty thousand years ago, a great sheet of ice, the Superior lobe, covered thisarea. At its farthest advance, it formed the St. Croix moraine, a series of high hills to thewest, south, and east. When it melted, it left behind vast deposits of gravel, sand, and clay.

The Anoka Sand Plain
After the Superior lobe retreated, another glacier, the Grantsburg sublobe, moved in from the southwest, filling the lowlands with ice. Again the climatewarmed, melting the ice and creating a lake that covered most of Anoka County - includingthis spot. Fine sand carried in the meltwater settled to the bottom. The lake disappeared when its water found an outlet into the Mississippi River, leaving the Anoka Sand Plain, an expanse of sand measuring 2,200 square km (850 square miles).

Dunes and Bogs
Beginning about eight thousand years ago, drier weather and wind formed sand dunes in some areas of the Anoka Sand Plain. Dunes often rise 9m (30 ft) or more above the surrounding land. Meanwhile, low-lying areas of the glacial lake basin are gradually fillingup with organic matter and evolving into bogs.

reverse side
Kettle Lakes and Outwash Plains
As the glaciers retreated, they left behind huge blocks of ice buried by gravel, sand, and clay. When the blocks melted, they left depressions, knownas kettles. Melting ice created thousands of kettle lakes in Minnesota. In many places, melting glaciers also deposited "outwash" plains of sand.

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Show me all markers in:  Ramsey, MN  |  Anoka County  |  55303  |  Minnesota  |  United States of America

Itasca Village Townsite
Grange Shrine
Geology of the Elk River Region
Rum River Dam
Perseverance Needed
The Stone House / Robert W. Akin
Why Settle Here? / Time to Play
The Gathering Place
Anoka Post Office
Bridging the Mississippi

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