The Essequibo River (Spanish: Río Esequibo; originally called by Alonso de Ojeda; Río Dulce) is the largest river in Guyana, and the largest river between the Orinoco and Amazon. Rising in the Acarai Mountains near the Brazil–Guyana border, the Essequibo flows to the north for 1,014 km (630 mi) through forest and savanna into the Atlantic Ocean. It has a total drainage basin of 156,828 km2 (60,552 mi2) and an average discharge of 154 to 178 km³/year. Territory near the river is argued over by Venezuela and Guyana. The river is administered by Guyana after being previously colonized by the British. Historically, Venezuela has claimed the Essequibo River as their most eastern border, though in practice it was under Dutch control.
