Placer, a N. E. county of California, bordering on Nevada, bounded N. by Bear river, S. by the American river and its Middle fork, and intersected by the N. fork of the American and other streams; area, 1,386 sq. m.; pop. in 1870, 11,357, of whom 2,410 were Chinese. The E. part is mountainous, being crossed by the Sierra Nevada, and is well timbered. Toward the Sacramento valley on the west the surface becomes more level, and in this portion there is much arable land; but the chief wealth is in the gold mines, of which there were 43 in 1870, viz.: 21 hydraulic, 18, placer, and 4 quartz. The county is traversed by the Central Pacific railroad and its Oregon division. The chief productions in 1870 were 102,402 bushels of wheat, 57,261 of barley, 61,209 gallons of wine, 169,033 lbs. of wool, 72,125 of butter, and 6,665 tons of hay. There were 1,767 horses, 1,563 milch cows, 2,575 other cattle, 26,596 sheep, and 7,421 swine; 1 manufactory of curled hair, 4 breweries, 14 saw mills, 1 pork-packing establishment, and 3 quartz mills.