River, central and northern Brazil.
Formed by several headstreams, it flows north through northeastern Mato Grosso state and central Pará state into the Amazon River near its mouth. Though approximately 1,300 mi (2,100 km) long, it is navigable for only about 125 mi (200 km) upstream from where it joins the Amazon; its central part is a series of rapids 400 mi (644 km) long. In the 1950s Xingu National Park was designated as a preserve for Brazil's Indians, including the Tchikao, who were threatened by extinction.