Portsmouth Mine Pit Lake

Infobox lake
lake_name = Portsmouth Mine Pit Lake
image_lake = Portsmouth 019.jpg
caption_lake = A view of the swimming area from the campground on the west shore of the lake.
image_bathymetry =
caption_bathymetry = Minnesota DNR map from data collected in 1996
location = Crosby, Minnesota
coords = coord|46|29|22|N|93|57|53.5|W|type:waterbody_region:US-MN|display=inline,title
type = artificial lake
inflow =
outflow =
catchment =
basin_countries = United States
length =
width =
area = convert|121|acre|abbr=on|lk=on
depth =
max-depth = convert|450|ft|abbr=on
volume =
residence_time =
shore =
elevation =
islands =
cities =

Portsmouth Mine Pit Lake, sometimes called the Portsmouth Pit, is the deepest lake in Minnesota at over 450 feet (137 m), according to the most recent Minnesota DNR data. The 120 acre (50 ha) artificial lake is a former iron mining pit in the Cuyuna Range that has since filled with water.

The Portsmouth Mine Pit is part of the Cuyuna Country State Recreation Area, located in Crow Wing County. The lake is within Crosby-Ironton 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.

References

* [http://stratocat.com.ar/fichas-e/1957/CBY-19570819.htm Details of the Manhigh II flight ]
* [http://www.dnr.state.mn.us/lakefind/showreport.html?downum=18043700 MN DNR Lake information - Portsmouth Pit]
* [http://www.dnr.state.mn.us/faq/mnfacts/water.html MN DNR MN Facts - Lakes, rivers & wetlands] 2003