The Luquillo Experimental Forest (LEF) is located in the rugged Sierra de Luquillo Mountains, 25 miles southeast of San Juan, Puerto Rico. It is the only tropical forest administered by the USDA Forest Service.

The Forest contains 27,890 acres. Elevation ranges from 100 to 3,533 feet above sea level. The climate is tropical. Average annual rainfall over the Forest is 120 inches per year. Topography is rugged, with 24 percent of the Forest exhibiting 60 percent slope or steeper.

The Forest has long served as a site for research, conducted by scientists of the Forest Service, the University of Puerto Rico, and around the world. It is uniquely suited to research on tropical forests and their management. Because of its wide elevation and precipitation range, five life zones occur within this small forest. These life zones are representative of more than one-third of the forested lands of the American tropics; 155 tree species occur in the Forest that grow elsewhere in tropical America. Access and facilities are as favorable for tropical forestry research as anywhere in the hemisphere.