The Tigre River (Spanish pronunciation: [ˈtiɣɾe]) is a Peruviantributary of the Marañón River west of the Nanay River. It is navigable for 125 mi (201 km) from its confluence with the Marañón. It forms from the confluence of the Ecuadorian rivers Cunambo and Pintoyacu at the Peruvian border. Like the Nanay, it flows entirely on the plains. Its mouth is 42 mi (68 km) west of the junction of the Ucayali River with the Marañón. Continuing west from the Tigre along the Marañón River we have the Parinari, Chambira, and Nucuray, all short lowland streams, resembling the Nanay in character. Tigre is Spanish for "tiger".