Among the petroglyphs at the site are nearly 100 carvings of atlatls, an ancient spear-throwing tool. There are also several carvings of animals with spears in them. (The carvings shown above are not part of one group, but are scattered throughout the site). Until the bow and arrow came along to replace it in this area around 500 years ago, the atlatl was THE weapon. 10,000 years ago, it was even used to hunt mammoth!
To help visitors understand just how effective it was, the Jeffers Petroglyphs has an atlatl range. The staff will take you out and demonstrate how to throw it, then let you try it for yourself. "Buffy", a full-sized target buffalo made of foam, will be waiting for your dart on the other end of the range. If you hit him, you will receive a "Buffalo Hunter" certificate to take home and show to your friends! Approximately 50 certificates are awarded each year.
They have a number of atlatls from all around the world for hands-on displays, as well as instructional handouts showing you how to make your own atlatls and darts. There are also a number of coloring pages for children. On special events, they have a "make-and-take" atlatl program, where you can make your own atlatl to go throw with. It's a very simple one, but it works and teaches you about the basics of the atlatl. Books about the atlatl, children's atlatl kits, maple atlatls, darts, and dart-making supplies are available in the gift shop.
For more information about the atlatl, you can check out the Northern Plains Atlatl Association's website. They are loosely based at the Petroglyphs, and the organizer of the NPAA is a volunteer atlatl instructor at the Petroglyphs.
Also, an enterprising soul wrote to all 50 states to see if the atlatl was a legal hunting weapon there. His responses are here.