largest of three iron (iron processing) ranges in northern Minnesota, U.S. (the others are Vermilion and Cuyuna). It extends 110 miles (180 km) from Babbitt (northeast) to Grand Rapids (southwest) at heights varying from 200 to 500 feet (60 to 150 metres), with a high point of 2,000 feet (610 metres). The great bulk of its iron-ore formation is hard magnetic taconite, which exists in thick layers up to 3 miles (5 km) wide. By the 1950s reserves of high-grade hematite ore, worked since 1892, had been depleted, and the lower-grade taconite was economically processed as pellets containing more than 60 percent iron. The chief mining centres are Hibbing and Virginia. Mesabi is an Ojibwa name meaning “giant.”