Gilpin, a N. central county of Colorado, lying chiefly in the foot hills; area, about 150 sq. m.; pop. in 1870, 5,490. The average altitude of the county is about 9,000 ft.,but the climate is mild. The surface is broken by mountain ranges. The valleys, watered by small streams, are fertile. It is one of the richest gold-mining regions in the world, and contains more than 90 quartz mills. In 1870 it produced bullion to the value of about $2,000,000. There are 9 hotels, 6 churches, 5 schools, 2 founderies, 2 smelting works, 1 chlorine reduction establishment, and 2 newspapers. The chief agricultural productions in 1870 were 21,665 bushels of potatoes and 172 tons of hay. Capital, Central City.