A W. Province Of The Argentine Republic, bounded N. and N. E. by Cata-marca, E. by Cordova, S. by San Luis, S. W. by San Juan, and W. by Chili, from which it is separated by the Andes; area, 35,000 sq. m.; pop. in 1869, 48,493. Besides the Andes, the province is traversed in a generally N. and S. direction by the Jagüé, Famatina, and Velasco or Rioja ranges, the second containing the Nevado peak, 17,050 ft. above the sea. Between these chains are vast plateaus and valleys. The only important river is the Ber-mejo, descending from the Andes in the northwest, and draining the valley of Jagüé. Gold, silver, copper, iron, tin, and quartz occur extensively in the Famatina chain, precious stones in that of Velasco, and nickel, lead, antimony, carbonate of soda, salt, nitrate of potash, and nitrate of soda elsewhere. There are now (1875) in operation two gold, seven silver, and two copper mines. Maize, wheat, cotton, olives, grapes, and various other fruits are extensively cultivated; and timber, gums, honey, wax, and cochineal and other dyes are very abundant. Cattle rearing is one of the chief occupations. The manufactures comprise leather, cotton and woollen fabrics, laces, rum, cordials, and preserved fruits, all of which, with vicuńa, guanaco, and puma skins, are largely exported.
In 1869 there were 3,000 children attending school. The province is divided into the departments of La Rioja, Arauco, Famatina, Vinchina, Guandacol, Independencia, Costa Alta, San Martin, and Belgrano.
A City, capital of the province, near the E. base of the Rioja mountains, 650 m. N. W. of Buenos Ayres; pop. in 1869, 4,489. It is situated in a vast plain, and has good streets and houses, with a parish church and three churches attached to convents. The surrounding country is remarkably fertile, and wheat and the vine are extensively cultivated. La Rioja was founded in 1591.