This is a ghost of the original Caloosahatchee River when it zig-zagged its way across Southwest Florida. Oxbows like this one were formed when the old river was converted into a canal by the U.S. Army Corps of Engineers. What's left of the old river has no flow and has become a home for exotic plants. Large yachts now travel the canal portion of the old river, which has been carved from 100 feet wide to over 500 feet wide, and has been dredged from 8 feet deep to over 20 feet deep.

Time Sifting in the Caloosahatchee

By Mark Renz

Before modern man had dreams of taming the wild, the Caloosahatchee was truly an awesome river. With as many as 600 twists and turns, it slithered like a snake for over half of its 60 mile journey. Near its headwaters east of LaBelle, it had a six-foot waterfall.

The water ran so clear that if it wasn't for the abundance of fish, you could easily see the bottom. A hundred years ago, the river averaged eight feet deep. But not today.

In hindsight, the changes may have been inevitable. We wanted to drain wetlands, harness flooding and cut a watery path from the west coast to the east for boat traffic. In the process, the Caloosahatchee River became Canal No. 43 on the U.S. Army Corps. of Engineer maps.

It's sad to think that a pristine river formed by global forces, has -- in the geological blink of an eye -- been destroyed by an upright animal with no foresight. Some of the alterations were necessary, especially for flood control for public safety. But most of the changes were for human conveniences - without regard for the rights and welfare of other living creatures - both plants and animals.

So what does a fossil hunter do with a dead river? He or she tries to resurrect what has died. The Caloosahatchee River bottom, which was once a repository for the remains of all the creatures that lived along its banks, has been relocated. Some of that bottom was dug up and dumped along the banks and up to a mile inland. If you know where to look, the bottom is still there. And it still contains the fossilized life forms from several million years past.

Have boat will travel

If you know someone along the Caloosahatchee River in Lee or Hendry counties, or are resourceful, there are places you can drive to and walk along the banks without needing a boat. But your best way to get to the fossil beds is by water. I have countless favorite spots on this river. It's an ideal place to "get a fossil fix" during the summer rainy season when the rivers are too high in other areas. There are public boat ramps every few miles. I started by just picking one and canoeing east or west. If I did well, I marked the spot on my map for a follow-up trip.

Here are my methods for the Caloosahatchee:

Bank Collecting (artificial banks dumped by the Army Corps. of Engineers)

Because the Corps. dredged the river, a lot of the river bottom has been dumped onto it's existing banks, and is now covered with shrubs and trees. I paddle close to the banks and look for white shell and beach sand showing through. (Use caution...often there are sharp-edged rocks just under the surface near shore)

In the white, gravelly-looking material, I use a small 12-inch, 3-pronged garden rake to scrape material into my screen. Then dry sift it, or dip it in the river depending on which method is the most convenient. Shark teeth are the most common finds, with great white, mako, snaggle-tooth, lemon, dusky, bull and sharp-nose turning up all along the river. I've only found one cow shark tooth and have only seen a few giant whites found. Most large mammal bones and teeth were broken up by the dredge operation.

There is usually no shade along the river and it can be very hot and humid during the summer. Wear a hat, sunglasses and sunscreen and take frequent dips in the river to stay cool. Bring more water with you than you think you will need. I've gone through as much as a gallon and half in the afternoon.

Bank Collecting (natural bank)

For the first year, I didn't look in the black, chocolate-colored sediment immediately above the white shell layer. I figured that if the shell layer had been dumped there from the river bottom, anything above it would have been naturally deposited in the last 100 years. But in many places, the shell was laid down naturally and the black soil above it contains Pleistocene fossils (1.8 million to 10,000 years ago).

Shoreline Collecting (in the water)

Keep an eye on the shoreline. If there aren't many boats out and the water is clear, you can often snorkel or just walk and look straight down into about six inches of water for material washing out of the bank (and bottom). Look for signs, such as gravelly white & black material.

This series of photos was taken as I was removing a mammoth tooth from a nature-formed bank. I saw a slight variation in the brown colors, more of a red showing through. Gently working around the area with a flathead screwdriver, I eventually worked out the tooth.

Can you spot the mammoth tooth? Here again, it was in an undisturbed part of the natural bank, very nearly hidden from view. Later, the same tooth once it was cleaned up and a bone preservative was applied.

Two mammoth vertebrae also removed from the natural bank, more than 20 miles away from each other. Notice the plant feeler roots surrounding one.

The horse hoof core and top toe bone were found on the surface along the Caloosahatchee River. The middle toe bone, found in the Peace River, was placed in the photo to show you where each bone is located.