thumb|upright=1.4|Lake Superior Iron Ranges
thumb|The Croft Mine Historical Park in [[Crosby, Minnesota preserves the headframe and railroad bridge.]]
thumb|Cuyuna iron-ore district (1918)
The Cuyuna Range ( ) is an inactive iron range to the southwest of the Mesabi Range, largely within Crow Wing County, Minnesota. It lies along a line between Brainerd, Minnesota, and Aitkin, Minnesota. The width ranges from 1 to 10 miles (1.6 to 16 km).
Discovery
Though covered by Pleistocene glacial drift up to 200 feet thick, 1859 surveyors noted compass deflection while in the area. The range was surveyed by Cuyler Adams, using a dip needle in 1895. With partners, he located ore by drilling in 1903. The word "Cuyuna" is an amalgamation of the first three letters of Cuyler's name with "Una", the name of his dog.
The Kennedy mine shaft reached ore in April 1908 and the first shipment was made via rail on 11 April 1911. Open pit mining started at the Rowe mine in 1912. In addition to the iron, the ore was rich in manganese, which was useful during World War I, with 32 mines operating. On February 5, 1924, a new tunnel was blasted too close to nearby Foley Lake, and water rushed in, killing 41 miners.
Geology
thumb|Binghamite, Cuyuna North Range, Minnesota, USA
The rocks in the district consist of tightly folded layers parallel to the axis of the Lake Superior Syncline. These folds trend to the northeast. The rocks have been slightly metamorphosed.