[1][2] The present lagoon is a remnant of what was once a large open expanse of water and one of the most important freshwater habitats for migrating waterfowl and aquatic birds in Puerto Rico.

Intensive cattle grazing and sugar cane production have greatly altered the original landscape.

In addition to the lagoon, there are uplands that include pastureland, abandoned sugar cane fields, and 263 acres (1.06 km2) in the foothills of the Sierra Bermeja.

These hills, geologically the oldest in the Caribbean, protect native forest with many endemic plant species.

This article incorporates public domain material from websites or documents of the United States Fish and Wildlife Service.