 At the end of the 19th century , several forms of industrial development shaped Minnesota . In 1882 , a hydroelectric power plant was built at Saint Anthony Falls , marking one of the first developments of hydroelectric power in the United States . Iron mining began in northern Minnesota with the opening of the Soudan Mine in 1884 . The Vermilion Range was surveyed and mapped by a party financed by Charlemagne Tower . Another mining town , Ely began with the foundation of the Chandler Mine in 1888 . Soon after , the Mesabi Range was established when ore was found just under the surface of the ground in Mountain Iron . The Mesabi Range ultimately had much more ore than the Vermilion Range , and it was easy to extract because the ore was closer to the surface . As a result , open @-@ pit mines became well @-@ established on the Mesabi Range , with 111 mines operating by 1904 . To ship the iron ore to refineries , railroads such as the Duluth , <unk> and Iron Range Railway were built from the iron ranges to Two Harbors and Duluth on Lake Superior . Large ore docks were used at these cities to load the iron ore onto ships for transport east on the Great Lakes . The mining industry helped to propel Duluth from a small town to a large , thriving city . In 1904 , iron was discovered in the Cuyuna Range in Crow Wing County . Between 1904 and 1984 , when mining ceased , more than 106 million tons of ore were mined . Iron from the Cuyuna Range also contained significant proportions of manganese , increasing its value . 
