The basic geologic facts of the Everglades are the same today as they always were - that is, this end of the state of the Florida, this end of the Peninsula, was up to about 7000 years ago off and on under water because of the freezing and melting of the polar ice cap. When the last water ran off -- the salt water ran off, when it was all ocean at one time -- it left the shape of Florida as it is now. It is shaped entirely of oolitic limestone, not coral rock as everybody says. There's bits and pieces of coral in it but it is a true oolitic limestone which is a sedentary rock occurring chiefly under water. So when the water ran off, this shape of the sedentary oolitic limestone was exposed and the outside currents began to shape the peninsula as we see it today. A gentle current coming down the Gulf of Mexico along the west coast and the piece of the great Florida Straits current which is a part of the greater Gulf Stream, the Florida Straits Current coming from between Yucatan and the western end of Cuba coming along shaping the whole East Coast. So the outsides of that mass of oolitic limestone was shaped by the salt water. But as the saltwater ran off, the interior which showed up was covered from, say, Orange County south, with a series of, well the saltwater ran off in streams and ponds and marshlands, and then the rain which had always been raining of course filled up the declivities left by the saltwater so that all the water coming down from below what is now Orange County was fresh. Freshwater coming down what we now call the Kissimmee Valley with marshlands and little ponds and all kinds of little meandering streams and tributaries down into the central declivity of Lake Okeechobee from which the Caloosahatchee River moved westward to the Gulf of Mexico with meanders. The meanders always indicate a very old stream of water. And the Caloosahatchee was there from many times when Florida was covered with ocean water and the ocean water ran off the Caloosahatchee was always there. It is very much older really than the 7000 years that we consider the present shape of the peninsula.
Over on the east side the Loxahatchee Slough and the St. Lucie River and those freshwater marshes and streams took the eastern overflow of Lake Okeechobee. But the main part of the water ran from the southern edge of rim of Lake Okeechobee, down into a great arc curving south and southwest making a sheetflow of water down the middle of the peninsula and that is the part we call the Everglades. Where the freshwater ran, the sawgrass grew. So where you find south of the Lake the sawgrass and the freshwater -- the water flowing and the grass standing still -- you find the true grassy Everglades -- an area of, say, from 40 to 80 miles wide, surrounded on the east by the east bank of the East Coast ?? which is a ridge of oolitic limestone between the ocean and the Everglades and on the west side a kind of a rectangular triangle where the Big Cypress is, which is like the west coast of the Everglades, a much larger area extending outwards into the Ten Thousand Islands. Now that shape of the land and the nature of the gentle incline down which the water has always run is just the same today as it always was. That's the geologic part of it. It has been changed superficially so that the River of Grass, as I called it, has been changed greatly. The Lake has been changed by being polluted, and the last thing the Engineers did was to run a canal down the meanders of the Kissimmee River and that changed that thing so that all the things that man did, say from like, well it began in '81 with attempts to drain it, everything man did was likely to be wrong because people in those days did not pay any attention to the main system and picture of the Kissimmee-Okeechobee-Everglades basin.