Lower Or Old (Span California. Baja or Vieja California), a territory of Mexico, occupying the peninsula extending N. W. from Cape San Lucas, lat. 22° 52' N., Ion. 109° 53' W., about 750 m. to lat. 32° 20' N., and having a breadth of from 30 to 150 m.; bounded N. by California, E. by the Colorado river, which separates it from Arizona and Sonora, and by the gulf of California, S. and W. by the Pacific; area, about 57,500 sq. m.; pop. in 1868, 21,645.

The population consists chiefly of Indians and mixed races, mostly residing in the southern portion of the peninsula. It is divided into eight municipalities (municipalidades), each having an alcalde, or juez del distrito, as its judicial head. The principal towns are La Paz, the capital, at the head of a bay on the S. part of the gulf coast, and Loreto, about 150 m. further N., both very small. The coasts are flat, sandy, irregular, and frequently indented by coves and bays, while, especially along the gulf, they are skirted by many small islands. The principal islands on the Pacific coast are Cedros and Santa Margarita; Guadalupe, about 120 m. N. W. of Cedros, also belongs to the territory. On the gulf coast are the islands of Ceralbo, Espiritu Santo, San Jose, Carmen, and Angelo de la Guarda. The principal bays on the Pacific coast, commencing at the north, are those of Todos Santos, San Quintin, Sebastian Viscaino, Ballenas, and La Magdalena, which for the last 50 years has been visited by American whalers, sealers, and fur hunters, who since 1854 have had regular establishments there. Entering the gulf, the first important bay is that of La Paz,, which penetrates the land S. from Espiritu Santo island some 25 m., with a breadth of from 6 to 10 m.

The cove opposite the town of La Paz may be reached by vessels drawing not over 18 or 20 ft. of water; this port is a stopping point for steamers from San Francisco to the ports along the Mexican coast. Loreto is, next to La Paz, the best harbor on this coast. Other ports are Los Angeles, and, near the head of the gulf, San Felipe Jesus. - The peninsula is of volcanic origin, and is traversed throughout by mountains, which may be considered a continuation of the Sierra Nevada and Coast ranges. It is divided into three regions. From Cape San Lucas due N. to Cape La Paz, in lat. 24° 20', about 100 m., stretches the chain known as Sierra de San Lazaro, having an average height of about 6,000 ft., and forming the backbone of the lower portion of the peninsula. Separated from this chain by La Paz bay, but commencing about the 24th parallel, is the Sierra de la Gigantea, a chain having an average elevation of from 3,000 to 4,000 ft., but.with occasional peaks 6,000 to 8,000 ft. high. It extends N. W. to about lat. 30° 35', a distance of 500 m., and adheres closely to the gulf shore, from which it rises almost perpendicularly, while on the west it declines gradually in gentle slopes or plateaus, with occasional broken tracts, toward the Pacific. About lat. 29° the Coast range commences, and from lat. 30° 40' the E. side of the peninsula, for a breadth of nearly 30 m. from this range to the head of the gulf and the Colorado river, is low and nearly level.

Between lat. 26° 40' and 27° 50' the peninsula suddenly extends W., having an average breadth of about 135 m., and a range of coast hills of considerable altitude stretches N. "W. and S. E. near the Pacific. In this region the land along the shore is low, and there are extensive lagoons. The mountains are in general barren and desolate near their summits; but at their base are cactuses of extraordinary size, and such of the valleys as have a sufficiency of water are very fertile. Only a few small streams fall into the sea, but there are several springs in the interior, sending forth streams which lose themselves in the sand. Along the coast lagoons there is much good soil, and in the plains and most of the dry river beds water is found a few feet below the surface. Where irrigation has been practised, the crops are abundant. Extending through nearly 10° of latitude, Lower California has a great variety of climate. For about 80 m. N. of Cape San Lucas the air is mild, being tempered by the sea breeze; from this section N. to Loreto, lat. 26° 16', the heat is excessive; but further N. the air is cooler. The summer temperature on the Pacific coast ranges from 58° to 71°; that of the gulf coast is hotter.

The sky is remarkable for its transparency and deep azure color, save at sunset, when it is often variegated by the most beautiful shades of violet, purple, and green. In winter there are heavy rains and terrific tornadoes. In summer and autumn, especially on the gulf coast, rain often falls from a cloudless sky. The vegetable productions of Lower California are maize, wheat, beans, peas, manioc, grapes, oranges, lemons, citrons, prunes, dates, plantains, pineapples, olives, and figs. The sugar cane has also been cultivated, and some cotton was raised by the Jesuits. Several varieties of the agave family are abundant, and many kinds of acacia trees, such as mesquites, algarrobas, and locusts, are common. Two varieties of native palms, bearing edible fruit, are frequently found. The pine, cedar, oak, wild plum, cottonwood, sycamore, willow, and elder are also met with. The principal animals are wild sheep, goats, horses, horned cattle, mules, and swine. The adjacent seas abound with excellent fish. The pearl oyster is found at intervals along the coast. It is most abundant in the bay of La Paz, near Loreto, and in the bays of Muleje and Los Angeles. Fossil remains are found in various parts. Argentiferous galenas are very common above Muleje bay, and pure sulphur occurs in the same region.

Copper ores are found in several places between the N. boundary and the old mission of Rosario, about lat. 31°, on the Pacific coast, and also on the N. gulf coast; the deposits on Ceralbo, San Jose, and Espiritu Santo island are very rich. Quicksilver is also said to have been found near Santa Cataljna mission, at the head of the gulf. The salt beds of the Pacific coast, from San Quintin to Magdalena bay, are numerous, and the salt is readily obtained. The mines on Carmen island are very rich, and large quantities of salt have been exported to San Francisco. The Mexican government has of late derived considerable revenue from these mines. Gold and lead are found, a mine of the former existing near La Paz. - Lower California was discovered by Cortes in 1536. About 1690 the Jesuits formed establishments here, and instructed the natives in agriculture and civilization. They practised irrigation extensively, and exported some agricultural products to the mainland of Mexico. The Jesuits were expelled in 1767, and the missions were placed under the charge of the Dominican monks of the city of Mexico, under whom they greatly declined; and in 1833 they were all secularized by act of congress.

In 1866 the Mexican government granted that portion of the peninsula lying between lat. 31° and 24° 20' to the "Lower California company" of New York, with considerable privileges. Their attempts at colonization, however, have not been successful.