In 1878 the state geologist, Professor N. H. Winchell, announced the existence of iron ore fit for steel production about Vermilion Lake in St. Louis County; but neither the university nor the state authorities took sufficient interest to cause a proper examination of the region to be made. George C. Stone of Duluth conducted explorations whose revelations led to the formation of the Minnesota Iron Company and the building of the Duluth and Iron Range Railroad in 1884. In that year 62,122 tons of ore were shipped from the mine opened at Tower. Four years later the railroad was extended to Ely, and 54,612 tons were carried from the Chandler mine. The product of the Vermilion range increased with astonishing rapidity. It was near a half million tons in 1888, and double that figure four years later. Marvelous as had been the development of the Vermilion range, it was eclipsed by that of another of which geologists had detected but faint indications. In November 1890, an exploring party of the Merritt Brothers of Duluth found iron ore at a point west of Virginia, near which the Great Mountain iron mine was later opened. A year after one of their explorers found ore turned up by the roots of a fallen tree. A shaft sunk on the spot struck the ore body of the Biwabik mine. From these beginnings date the developments of the Mesabi iron range, lying some twenty miles south of and parallel with the Vermilion range, but extending much farther to the west. In 1892, 4245 tons of ore were shipped over the railroads which had been built out from Duluth to the Mesabi mines. Three years later the shipments were nearly three millions of gross tons; in 1900 they had swelled to nearly eight millions, and in 1907 they touched twenty-seven and a half millions. The shipment in the year last named from a certain single mine was 2,900,493 tons. The Mesabi ores are of the “soft” variety, lie near the surface, and are in large part mined by means of steam shovels dumping into cars; these, in the shipping season, are at once dispatched to the lake ports, where the ore is transferred to vessels which carry it below. The output of the Vermilion range has remained under two millions a year, except in a single case. The ores of both ranges are of the variety known as hematite, with great differences of physical structure. Much of them yield seventy per cent. of pure metal. Ore containing less than fifty-five per cent. of iron is not now considered marketable, and there are enormous masses of such low grade ore left untouched by the mine operators. At least 1,500,000,000 tons of ore marketable under present conditions have been located and measured. The state tax commission in 1907 raised the valuation of 2116 ore properties, containing 1,192,509,757 tons, from $64,500,000 in 1906 to $189,500,000.