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How Did Minnesota Get So Many Lakes?

MINNEAPOLIS (WCCO) -- Minnesota is known as the Land of 10,000 Lakes, but the real count is 11,482. According the Minnesota Department of Natural Resources, a lake is considered an official lake when it is 10 acres or larger.

Depending on how lakes are defined, this puts Minnesota right at or near the top of the list in the country when it comes to quantity. So, how did Minnesota get some many? Good Question.

(Hint: It's not actually the footprints of Minnesota legends of Paul Bunyan and Babe the Blue Ox.)

"We have a lot of lakes because we have a very young landscape and a landscape that was rearranged by glaciers," says Carrie Jennings, a geologist and Research and Policy Director for the Freshwater Society.

Two and half million years ago, the world started to see episodic Ice Ages. Glaciers, made of an accumulation of ice, snow and rock, would come in and out of Minnesota over the next two million years. They would cover parts of the U.S., then recede, then come back and continue to repeat the cycle.

"The glacier pushes into the landscape and erases any drainage that was here before," says Jennings. "As it melts, as it retreats back, it creates a new landscape."

The glaciers can create lakes in a number of ways.

The smaller lakes around Gull Lake were created when ice blocks broke off the glacier, were buried in sediment and eventually melted.

The chain of lakes at Orchard Lake in Lakeville was created by tunnels underneath the glacier that were spewing out water.

Lake Superior was created when a big ice lobe came off the main sheet and focused its flow in that spot for a long time.

The last time glacier fully receded from Minnesota was 14,000. It left behind a lumpy terrain.
Compared to other places in the U.S., that's a relatively young landscape. For example, Illinois' lakes were created 10,000 or so years before Minnesota's and have since mostly dried up, according to Jennings.

Jennings said Minnesota happened to be in the best place for lakes to form. No glaciers went west of the Missouri River. Wisconsin, which boasts more than 15,000 lakes – many of them smaller, was never fully glaciated like Minnesota. Jennings also calls what their glacier left behind less messy.

"I think we're lucky to have so much access to the water," she says.

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