The Mesabi iron-mining district or range, is in north-eastern Minnesota, 60 to 85 miles west of Lake Superior. The Mesabi Range, in this report, includes the iron-mining belt, ¼ of a mile to 3 miles wide, that extends for 120 miles in a northeasterly direction across Itasca and St. Louis Counties. It is the area of economically important iron-bearing formation and associated rocks, now mostly buried under glacial drift.