Cape Sable
Cape Sable is a coastal landmass forming the southwestern tip of the Florida peninsula and the southernmost point of the continental United States mainland, located within Everglades National Park in Monroe County, Florida.[1][2] It comprises three principal projections—Northwest Cape, Middle Cape, and East Cape—extending into the Gulf of Mexico and Florida Bay, with East Cape Sable marking the precise latitude of 25°07′13″N.[3] The area's geography features narrow sandy beaches backed by black mangrove thickets, coastal marl prairies, and shallow interior lakes such as Lake Ingraham, historically supporting expansive freshwater marshes now diminished by anthropogenic canals and natural erosion processes.[1][4] Ecologically significant, Cape Sable provides essential habitat for rare species including the endangered Cape Sable seaside sparrow (Ammodramus maritimus mirabilis), which inhabits the remaining short-hydroperiod prairies, alongside diverse wading birds, reptiles, and marine life adapted to the interface of freshwater and saline environments.[5][6] Its remoteness, accessible chiefly by watercraft or lengthy overland trails from the park's Flamingo visitor center, underscores its wilderness character, though the region faces ongoing challenges from sea-level rise, storm surges, and sediment transport dynamics that have led to shoreline retreat and habitat conversion to saltwater-tolerant mangroves.[1][4]
Geography
Location and Topography
Cape Sable constitutes the southernmost point of the continental United States mainland, situated at approximately 25°07′N 81°05′W in southwestern Florida's Monroe County.[7] This coastal landmass forms part of Everglades National Park and projects southward into the Gulf of Mexico, delineating the boundary between the gulf waters to the west and the inland bays to the east.[1]
The cape encompasses roughly 80,000 acres of low-relief terrain, characterized by sandy beaches fringing the exposed Gulf coastline, backed by narrow zones of mangrove thickets, and transitioning inland to expansive marl prairies and shallow wetlands.[8] Its physical extent lies between the Gulf of Mexico on the west, Whitewater Bay to the northeast, and Florida Bay to the southeast, creating a triangular promontory shape vulnerable to marine influences due to elevations typically at or near sea level.[1]
Cape Sable features three principal subdivisions along its shoreline: East Cape, marking the southeastern terminus and actual southernmost latitude; Middle Cape, also designated Palm Point, positioned centrally; and Northwest Cape, extending toward the northwestern gulf edge.[9] These points are separated by broad, low-lying tracts that include scattered shallow lakes and subtle topographic highs formed by ancient limestone ridges.[2]