The area also contains a number of remnants that showcase the military history of the region: a former US Army lookout post on top of El Morrillo, and a number of bunkers built during the Second World War.

[2] The forests and wetlands were acquired by the Puerto Rico Department of Natural and Environmental Resources in 1984, and it was proclaimed the Humacao Wildlife Refuge in 1986.

The reserve is important for the revitalization of local ecosystems that were threatened by the industrial development of the area during the 19th and 20th centuries such as mangroves, wetlands and its distinctive Pterocarpus forest.

[3] In addition to hiking trails and picnic areas, there is kayaking and bike rentals on site.

[4] One of the most popular hiking trails lead to a hill called El Morrillo, which offers views of the reserve, Punta Santiago Beach, El Yunque, Cayo Santiago (popularly known as "Monkey Island") and the island of Vieques.