United States Steel’s Pilotac plant, 1955. The Oliver Mining Division of USS built the Pilotac plant to develop taconite processing methods. Minntac was the result of these efforts.

United States Steel’s Extaca plant, 1960. The Oliver Mining Division of USS built the Extaca plant to accompany the Pilotac plant in the development of feasible taconite processing methods.

A sign outside a business promoting a “yes” vote on the taconite amendment, 1964.

Taconite Amendment bumper sticker, 1964. To promote a “yes” vote on the taconite amendment to rewrite the tax structure that affected taconite operations, advocates made bumper stickers to advertise their cause.

Erie Mining Company’s Concentrator Building under construction, ca. 1954. The Concentrator Building—where taconite is finely ground and iron ore is removed from the rock—was built near Hoyt Lakes around 1954.

Hoyt Lakes under construction, 1955. Hoyt Lakes was built to accommodate workers and mine staff by the Erie Mining Company—the Iron Range’s second major taconite facility.

Taconite Harbor, 1956. Taconite Harbor was built to ship ore mined and processed at Erie Mining Company in Hoyt Lakes to steel mills on the Great Lakes. Concentrated ore was shipped from Hoyt Lakes to Taconite Harbor on a private railroad.

First Train of Taconite to Silver Bay, Minnesota, 1955. The first train of taconite from Reserve Mining Company’s Peter Mitchell Pit was shipped to the concentration facilities in Silver Bay in 1955.

Taconite prospectors at Sulphur Camp, ca. 1916. To access Sulphur Camp, prospectors would have to take a rail cart, pictured here, from Mesaba Station. Seated to the far left is E. W. Davis.

Cookhouse at Sulphur Camp, 1916. Sulphur Camp was the location of early taconite research, near current-day Babbitt, Minnesota. Peter Mitchell, a prospector from Michigan, explored the area and found that taconite was plentiful on this part of the Iron Range.