Sonoma, a N. W. county of California, bounded S. E. by San Pablo bay and W. by the Pacific ocean, and watered by Russian, Santa Rosa, Petaluma, and Sonoma rivers; area, 1,400 sq. m.; pop. in 1870, 19,819, of whom 473 were Chinese. The N. part is mountainous, being traversed by spurs of the Coast range, which are generally well timbered. The valleys are very fertile, and Sonoma valley is celebrated for its vineyards. In the N. E. part of the county are the geysers, a collection of hot springs. Gold, silver, copper, quicksilver, and coal occur, but not generally in paying quantities. The county is traversed by the San Francisco and North Pacific railroad. The chief productions in 1870 were 618,425 bushels of wheat, 145,792 of Indian corn, 323,961 of oats, 195,456 of barley, 369,154 of potatoes, 308,496 gallons of wine," 230,394 lbs. of wool, 1,060,266 of butter, 246,900 of cheese, and 35,571 tons of hay. There were 10,616 horses, 1,110 mules and asses, 14,960 milch cows, 16,592 other cattle, 58,387 sheep, and 28,588 swine; 4 manufactories of carriages and wagons, 5 of cooperage, 5 of cabinet furniture, 1 of iron castings, 5 of wine, 13 of saddlery and harness, 2 of sash, doors, and blinds, 8 of tin, copper, and sheet-iron ware, 5 flour mills, 4 tanneries, 3 currying establishments, 3 breweries, and 18 saw mills.

Capital, Santa Rosa'.