Bedrock geology of the southwestern part of the North Range, Cuyuna district, Minnesota

The Cuyuna manganiferous iron-ore district is in central Minnesota in Morrison, Crow Wing, and Aitkin Counties.  The length of the district is about 68 miles, extending northeastward from a point near Randall, in Morrison County, to a point 11 miles east of the community of Hassmann in Aitkin County; the maximum known width is about 25 miles near the center of the district.  Current mining activity is confined to a much smaller area, commonly called the North range, about 10 miles long and 3 miles wide near Crosby and Ironton in Crow Wing County.  The average annual production of iron ore and manganiferous iron ore during 1940-50 was slightly less than 3 million tons.