 Most of South Florida's hardwood hammock habitat was lost to urban and suburban development.There is a 2.16 acre (8,740 m2) hole (officially known as the "Keystone Pit") in the refuge, which manager Steven Klett has wanted to fill in order to revitalize the hammock habitat.The pit was dug 30 to 40 years ago in order to obtain fossilized coral to build and decorate fireplaces and other types of architecture (much of the limestone rock was mined as well).