Matto Grosso (Port, thick hrushwood), a province of Brazil, bounded N. W. and N. by Amazonas and Grao Para, E. and S. E. by Go-yaz, Sao Paulo, and Parana, S. by Paraguay, and S. W. and W. by Bolivia; area, 551,575 sq. in.; pop. about 100,000. This province, the largest in the empire after Amazonas, forms the western portion of the highlands of Brazil, comprising the Amazon-Paraguay watershed, which is so low that canoes ascending the Ta-pajos from Santarem are crossed over and floated on the Paraguay to descend to Villa Maria. From the transversal ridge forming the watershed just referred to are several minor chains stretching N. and S., separated by deep valleys and immense plains covered with dense forests, which give the name to the province, and afford inexhaustible quantities of timber suited for every species of construction, and a great variety of precious cabinet woods. The Tapajos and Xingu rivers rise in the central portion and flow N. to the Amazon, while the Paraguay flows southward, forming part of the S. W. boundary line, and all receive the waters of innumerable streams, which elsewhere would rank as grand rivers.

The Gua-pore or Itemez forms with the Madeira almost the whole of the remainder of the western boundary; and the eastern and southern boundaries are constituted by the Araguay and Parana respectively. Gold is found in nearly every direction; but the mines, like those of diamonds, once extensively worked, especially in the region surrounding Cuyaba, are now mostly abandoned owing to the cost of working them, as the gems and the gold no longer occur near the surface. Copper, iron, and many other metals abound in the hills. The soil is extremely fertile, and the chief occupations of the inhabitants are agriculture and cattle raising. The principal commodities exported are hides, ipecacuanha and other drugs, and balsams, all of which are sent to Rio de Janeiro by caravans of mules. Millet, rice, and manioc are cultivated, as are also sugar, tobacco, and cotton. The chief impediment to colonization is the absence of adequate means of transport to the centres of consumption and the seacoast. Capital, Cuyaba.