Location Crosby, Minnesota Basin countries United States Max. depth 450 ft (140 m) | Type artificial lake Surface area 121 acres (49 ha) Area 49 ha | |
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Similar Cuyuna Range, Portsmouth Campground, Lake Ore‑be‑gone, Milford Mine, Crosby Memorial Park | ||
Portsmouth Mine Pit Lake, sometimes called the Portsmouth Pit, is the deepest lake completely within the state of Minnesota. It has a depth of over 450 feet (137 m), according to the most recent Minnesota DNR data. Lake Superior, over 700 feet deep off the north shore of the state, is technically deeper. The 120-acre (49 ha) artificial lake is a former iron mining pit in the Cuyuna Range that has since filled with water.
Map of Portsmouth Mine Pit Lake, Crosby, MN 56441, USA
The Portsmouth Mine Pit is part of the Cuyuna Country State Recreation Area, located in Crow Wing County. The lake is within Crosby city limits.
In the last five years, the Minnesota DNR has repeatedly stocked the lake with brook and rainbow trout.
On August 19, 1957, the mine pit, then not yet filled with water, served as launch site for a big stratospheric balloon; the second flight of the Air Force's Project Manhigh.