The Environmentally Endangered Lands program in Miami helped to save this area from–believe it or not– overdevelopment. It started in 1974 as a “covenant” program around the same time that the population and development were booming, and it got private land owners involved in conservation.
Upwards of 71% of Miami-Dade County is protected. That’s right, only 29% is developed, despite what you might think based on a drive through Brickell and Little Havana. Most development in Miami-Dade sits atop the Atlantic Ridge, a long strip of elevated rock near the coast, which is relatively higher and dryer than the rest of the swamp. Lest we get too self-satisfied, we should remember that the Everglades used to cover all of South Florida before it was chopped to pieces, so even 71% of one county represents a small percentage of the original Everglades.
Private land conservation is limited but vital; most of the protected land is federal. Miami-Dade County is the only county in the U.S. with two national parks: Everglades National Park, and Biscayne National Park. Plus, the Big Cypress Preserve adds another huge swath of land to the county. Check it out.