The Rio Cupeyes (CUPE) core aquatic wadeable stream field site is part of the NEON Altantic Neotropical domain 04. The site is located in a rainforest area within the mountains of western Puerto Rico. The Rio Cupeyes is one of the most pristine 2nd order streams on the island, and is part of the Guanajibo River watershed in the Maricao State Forest. The Commonwealth of Puerto Rico manages the area. This wilderness area is used primarily for fishing and other recreational activities.The area is made up of old and second growth tropical moist and wet forest. And the Rio Cupeyes represents an increasingly rare intact Puerto Rican stream ecosystem. Automated stream sensors, and meteorological stations collect data year round and NEON field scientists collect field observations of aquatic plants, animals, biogeochemistry and more. Due to logistical and permitting issues, this aquatic site does not have groundwater wells. Total data products collected at this site: 76.