CROSBY, Minn. (WCCO) — Think about all the great places to go scuba diving. There’s the Great Barrier Reef in Australia, or the Caribbean with its bright colorful fish. Or how about swimming with northern pikes in the Brainerd Lakes region?

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Even though it will never be mistaken for the tropics, there are clear lakes in the Crosby-Ironton area giving divers an underwater adventure that doesn’t require a plane trip.

“Yeah, we have 30 to 40 (people) on a good night,” said Todd Matthies, a master diving trainer who leads dozens of diving expeditions each year. “Most times it’s always at least 20 people.”

They’re doing it in lakes that weren’t even here 40 years ago. You see, this used to be an active mining section of the Cuyuna Range, rich with iron ore. From the turn of the century to the 1970s, crews would pump water out so they could keep digging deeper.

“But eventually, when they quit mining,” said Matthies, “they shut the pumps off, the natural water table rose back up and filled them back up.”

What’s left now are lakes in a remote area where no rivers or streams can bring in sediment or lawn chemicals to contaminate the water.

“The visibility is really good for Minnesota lakes,” said Jeff Adams, a regular diver from St. Cloud.

The area is now known as the Cuyuna Country State Recreation Area. The DNR has stocked the new lakes with sunfish, bass, northerns and a few walleye.

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“If you just sit real still, the fish will surround you,” said Darlene Matthies, who also leads diving trips. “There’s generally a lot of sunfish, bass … and they’re just really kind of neat to watch.”

There are also remnants of the old mining operation underwater, which is part of the fun for divers to discover.

“Out over there by that island, there’s the old stairway that the miners used to get down,” said Adams, pointing. “We call that Stairway to Hell. And then at the bottom, there’s a little skull that someone placed there, like a metallic skull that they placed so you can go down there and see it.”

There are also sunken vehicles and boats — and even mature trees that used to grow in the iron pits.

“Swimming through the trees is a blast, because it kind of makes you feel like you’re in Sleepy Hollow,” said Adams. “It’s kind of creepy.”

The largest pits are 520-feet deep, but most of the interesting sights can be seen within 40 to 50 feet of the surface.

Most of the tours are led by the Minnesota School of Diving, which is owned by Todd Matthies and his father, Bill.

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They coordinate about 70 “fun dives” between May and October each year.