Casei River

The Casei River (), sometimes also spelled Casey River (Río Casey),Municipio de Las Marías. (February 2024). Las Marías Plan Final Ordenación Territorial (Redacted Version). Retrieved September 8, 2025, from https://jp.pr.gov/wp-content/uploads/2024/02/Plan-Final-Las-Marias_Redacted.pdf is a tributary of the Añasco River (Río Grande de Añasco) that flows through the municipalities of Las Marías, Mayagüez and Añasco in western Puerto Rico. It originates in the mountains of Las Marías, from where it flows northwest towards the Añasco Valley, creating a natural municipal boundary between Las Marías and Mayagüez along its path.

See also List of rivers of Puerto Rico

References

External links USGS Hydrologic Unit Map – Caribbean Region (1974) Ríos de Puerto Rico