The Everglades National Park established in 1947 protects over 1.5 million acres of land and provides refuge for endangered plants and animals, but unlike other national parks it does not control its own water supply. In 1974, Congress created the Big Cypress National Preserve to protect part of the Big Cypress Swamp and endangered species within it, while still allowing activities like oil exploration, cattle grazing, and hunting. Hurricane Andrew in 1992 destroyed 70,000 acres of mangrove forest within the Everglades park.