Formoso River (Rondônia)
The Formoso River is a river of Rondônia state in western Brazil.
It is a tributary of the Jaci Paraná River.
In its upper reaches the Formoso River defines the western boundary of the Guajará-Mirim State Park.
The park has two support bases on the banks of the Formoso River that are used by researchers and inspection teams.
