From what remains we can begin to gauge the extent of the loss and by 2012, despite the destruction of ancient sites, archaeologists had identified as many as 97 surviving mounds and earthworks in the Lower Mississippi Valley, with several others found as far afield as Florida, thought to be in the range of 5,000 years old.1 Very few of these sites have yet been subject to radiometric dating, but of the 16 that have, with a combined total of 53 mounds and 13 causeways, all are more than 4,700 years old2—and many are much older than that.
