Pierina Benites conducted research to estimate the entrance fee to National Park Tingo Maria in Peru. This park is the third most visited in the country and current charges only apply to one of the many attractions of the park. The results will allow the charges to be adjusted to a demand function, which will contribute to greater revenues and more efficient management. Pierina is an economist at the Universidad Agraria La Molina in Peru. This project was supported by the John D. and Catherine T. MacArthur Foundation.