Comments are appreciated, especially if you have alternate thoughts or criticism.
An example is shown below:
This image was offered by Tim, http://wakinguponturtleisland.
A discussion of a specific group of rock cairns in the Missouri Ozarks, first documented in 2004. The purpose is to seek data and clues to the origin of the builders, their purpose, and the probable dates of use. As of Feb 2012, 27 cairns have been identified, ranging in volume from about 0.8 to 16 cubic meters.