Iron-bearing rocks were noted by the Minnesota State Geologist Henry H. Eames in 1866. Iron ore was discovered north of
Mountain Iron on November 16, 1890, by J. A. Nichols of the
Merritt brothers. The range was defined by 1900. Initially underground mines were employed, but these gave way to open pits so that by 1902, half the operations were conducted this way. The last underground mine closed in 1960. Natural ores eventually gave way to iron-ore concentrates from magnetite taconite so that by 1965 one third of production came from these pellets. Much of the softer ore was formed close to the surface, allowing mining operations to be conducted via open pit mines. The world's largest open pit iron ore mine is the
Hull–Rust–Mahoning Open Pit Iron Mine in
Hibbing. In the early years of mining from the late 19th century until the 1950s, mining focus was on high grade ore that could be processed into
steel without much change. However, when that supply dried up, focus shifted to lower-grade ore (taconite) which requires extensive processing at large mining-processing facilities before moving to port. The mined ore is then transported, primarily by the
Canadian National Railway, to the ports of
Two Harbors and
Duluth, and by
BNSF Railway to
Superior, Wisconsin. At Duluth, trains of up to eighty 100-ton open cars are moved out on massive
ore docks to be dumped into
lake freighters with
tonnages of up to 60,000 for shipment to
steel mills in
Indiana and
Ohio. Dormant and exhausted open pit mines are a common feature along the Iron Range. Some of these sites have been redeveloped for other uses. For instance, the Virginia Pilot is a project which focuses on redeveloping the grounds adjacent to the old mines into low- to moderate-income residential space. The
Hill-Annex Mine became a state park and offered tours to visitors who wished to learn about mine operations. The park was closed in 2024 as mining had become feasible again. Currently, there are six mining-processing facilities in operation on the Iron Range.
Cleveland-Cliffs owns and operates Northshore Mining, which has mining operations in Babbitt and crushing, concentrating (grinding) and pelletizing operations in Silver Bay, along with United Taconite which has mining operations in
Eveleth and crushing, concentrating and pelletizing operations in
Forbes.
Arcelor Mittal owns and operates the Minorca Mine and Plant with mining operations near
Biwabik and
Gilbert and a crushing, concentrating and pelletizing facility near Virginia.
United States Steel owns and operates both KeeTac and Minntac with mining and processing facilities in
Keewatin and Mountain Iron respectively. Hibbing Taconite operates a mine and plant between Hibbing and
Chisholm. Mesabi Metallics is constructing a mine/plant near
Nashwauk to mine and process taconite.
Steel Dynamics and
Kobe Steel formerly owned and operated Mesabi Nugget near
Hoyt Lakes which did not mine its own material but produced high-iron content nuggets from purchased iron ore concentrate. Magnetation, Inc. formerly produced iron ore concentrate reclaimed from tailings with company-designed high-power magnetic separators to produce concentrate to sell and ship throughout the world. File:Hibbing Open-pit iron mining 1906.jpg|Open-pit iron mining with five-ton steam shovels, Hibbing, Minnesota File:Duluth Ore Docks.jpg|Duluth Ore Docks File:Mahoning-overlook.jpg|Hull–Rust–Mahoning Open Pit Iron Mine ==Rockefellers' interests==