The Deering Estate at Cutler features the geological formation known as the Miami Rock Ridge, which traverses most of Miami’s Atlantic coast. It is most prominent and visible in southern Miami-Dade County, particularly at the Estate. The ridge forms a barrier between Biscayne Bay and the interior of the southern Florida peninsula, establishing a geological basin that facilitated the development of the Everglades by helping to retain water and direct its flow from Lake Okeechobee. Cutler Creek, and the pre-channelization Cutler Slough, located on the Estate are examples of only a few naturally occurring historical wetlands/waterways that cut across the ridge thereby allowing water to move directly into Biscayne Bay. The Miami Rock Ridge is an important foundation for the Miami area, and its visible outcrops at the Estate present a rare opportunity for up-close experiences with large-scale geologic and hydrologic elements. The Miami Rock Ridge in the Deering Estate at Cutler also features excellent examples of karst topography, which is characterized by solution holes and caves created by historical movement of freshwater through limestone. These features are common on parts of the Estate and represent a unique component of Florida geology. These features typically drain quickly and only hold standing water for short periods of time following heavy rains. Vegetative structure of solution features often is that of a mature forest around its exterior. The steep rock walls generally are covered by mosses, liverworts, and ferns with occasional herbs and shrubs in crevices, and can include such rare and threatened species as Venus’-hair fern and least halberd fern. Solution features at the Estate include a large open sinkhole with three carved steps. One of the largest solution holes on the Estate houses the Cutler Fossil Site. In addition, regional lowering of the freshwater table over the past century has drained and exposed numerous interconnected shallow aquatic and terrestrial caverns.