Houghton, a N W. county of the upper peninsula of Michigan, bounded N. W. by Lake Superior, indented on the N. E. by Keweenaw bay, and drained by Sturgeon river and other streams; area, about 2,000 sq. m.; pop. in 1870,13,879. The surface is uneven and rocky, the N. W. portion consisting of the upper half of Keweenaw point, a peninsula lying between Lake Superior and Keweenaw bay, through which runs the Mineral range, and which contains Torch lake and Portage lake, discharging into the bay. Silver and iron ore are found, but the great wealth of the county is in its copper mines, which are situated in the Mineral range near Portage lake, the most productive being the Calumet and Hecla mine on the N. border. According to the census of 1870, there were 11 copper mines, employing 2,961 hands, and producing $3,231,888 worth of ore. The product of 1872 was 12,602 tons (four fifths of the product of the Lake Superior region), of which the Calumet and Hecla mine yielded 9,800 tons. The ore is in a nearly pure state. The chief productions in 1870 were 8,595 bushels of oats, 22,040 of potatoes, and 703 tons of hay.

There were 3 manufactories of clothing, 2 of iron castings, 1 of machinery, 1 of soap and candles, 12 of copper (milled and smelted), 4 of tin, copper, and sheet-iron ware, 4 breweries, 2 planing mills, and 5 saw mills. Capital, Houghton.