The Balsas River (Spanish Río Balsas, also locally known as the Mezcala River, or Atoyac River) is a major river of south-central Mexico. The basin flows through the states of Guerrero, México, Morelos, and Puebla. Downstream of Ciudad Altamirano, Guerrero, it forms the border between Guerrero and Michoacán. The river flows through the Sierra Madre del Sur, and empties into the Pacific Ocean at Mangrove Point, adjacent to the city of Lázaro Cárdenas, Michoacán. Several rapids along the course of the Balsas River limit its navigability and thus the river has been largely used for generation of hydroelectric power, flood control and irrigation.
