This Is The Deepest Lake Totally Inside Minnesota’s Borders

The deepest lake in all of Minnesota is just outside a little town that displays its giant signature Serpent.

Nestled in the heart of the Cuyuna Range near Crosby, Minnesota you'll find Portsmouth Mine Pit Lake.

Portsmouth stands as Minnesota's deepest lake entirely within state borders, plunging to an impressive depth of 450 feet.

While Lake Superior claims greater depths, it shares its waters with Canada, making Portsmouth Mine Pit unique in Minnesota's aquatic landscape.

Originally an iron mining pit from the region's industrial past, nature has reclaimed the space, filling it with crystal-clear water.

The lake's extraordinary depth and water quality have made it a destination for both recreational divers and fishing enthusiasts.

The surrounding Cuyuna Country State Recreation Area offers visitors more than just deep waters.

The lake's steep walls, formed during its mining days, create a dramatic backdrop for outdoor activities.

These red-earth cliffs contrast beautifully with the lake's turquoise waters, particularly striking during sunrise and sunset.

Today, Portsmouth Mine Pit Lake serves as a testament to environmental recovery, transforming from an industrial site into a natural wonder that draws visitors from across the state and beyond.

Its depth and clarity make it a unique part of Minnesota's rich landscape of lakes.