PORTO VELHO

city, capital of Rondnia state, western Brazil. It lies along the south bank of the Madeira River, a tributary of the Amazon. It was installed as the municipal seat in 1915. Prto Velho serves as its region's commercial, transportation, and communications centre. It is the head of navigation on the Madeira and is the northern terminus of the 228-mile (367-kilometre) Estrada de Ferro Madeira-Mamor, a railroad built in 1913 to circumvent rapids between Prto Velho and Guajar-Mirim and to carry rubber from Mato Grosso state and northeastern Bolivia, the borders of which lie 100 miles (160 km) southwest. Tin ore is mined in the vicinity. Lumber and medicinal plants and oils are also exported from Prto Velho, which has a commercial airport. Prto Velho is on the highway between Manaus and Rio Branco, with a highway extending to So Paulo. Pop. (1980 prelim.) 101,644.