river that rises in the highlands east of the Ucayali River in east-central Peru. It flows northward through Acre state, Brazil. Entering Amazonas state, Brazil, it meanders eastward and then east-northeastward, emptying into the stretch of the Amazon River known as the Solimões River, near Tamaniquá. The most winding river in the Amazon basin, the Juruá is calculated to exceed 2,040 miles (3,283 km) in length; yet it descends from only 1,486 feet (453 metres) above sea level. It is navigable for more than 600 miles (950 km) above its junction with the Amazon. Its banks are sparsely inhabited, and many of its tributaries were first mapped via satellite in the late 1970s.