The terrain of the Everglades is extremely low and flat, with the highest point only about 8 feet above water.
The bedrock beneath the Glades is unusual. Known as oolite or “egg stone,” oolite granules resemble a cluster of fish eggs. This is the result of South Florida repeatedly sinking into the sea and then re-emerging from it, which has occurred at least 4 times in recent geologic history.
A visit to the Everglades is almost like a visit to the Caribbean: Everglades plants are more akin to those of the Caribbean than North America. The gumbo limbo with its reddish bark and twisting branches is one of the best-known examples.
Although tree hammocks are found throughout the park, the Everglades primarily are a shallow plain of sawgrass growing in water only 6 inches deep.
This blanket of water has been likened to a tropical, primordial soup of algae and bacteria. Unappetizing as that may sound, it nourishes snakes, turtles, fish, and insects, which in turn feed the incredibly rich population of birds.
Traditionally the Glades’ most important water source has been Lake Okeechobee, located 60 miles north of the park. Each summer, Okeechobee (second-largest fresh water lake in the continental United States) would overflow and send a sheet of water 50 miles wide that moved over the landscape.
The water advanced about 100 feet a day, thoroughly watering and flushing the sawgrass, eventually reaching the mangrove estuaries on the Gulf of Mexico.
This annual flood was always followed by a 6-month dry season. Birds and animals adapted and patterned their lives based on this alternating cycle.