river in central and eastern Nicaragua. It rises in the central highlands southwest of Matagalpa city and flows alternately northeastward and southeastward, between the highlands of the Darién and Huapí mountains. It then meanders eastward through the lowlands of eastern Nicaragua, picking up its major tributary, the Tuma, and empties into the Caribbean Sea at the town of Río Grande.

Although the Matagalpa's total course measures 267 miles (430 km), only the lower stretch is navigable. Nicaragua's (Nicaragua) first major hydroelectric plant was constructed and an artificial lake created at its headwaters.