Despite coming prepared to go look at numerous petroglyph sites, this ended up being the only one we got to.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/84632209@N00">Philip Brewer</a> from Champaign, IL
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/bradipo/41641003694/">Petroglyphs</a>