The Clam Shell Rock Art Site is one that is near Fredonia, Arizona that we haven't visited yet. Turn off of US-89A in Fredonia onto East Dobson Street. After a block turn left onto North 1st East and then right onto Rhea. From there it is about 3.9 miles to pullout below the site. Look up and spot the boulder that resembles a clam shell. There are both petroglyphs and pictographs at this site.
Included with this post is the GPS file and map that we plan to use for our first visit. If you don't want to wait for us to get around to it feel free to try the GPS file and map for yourself. With no guarantee, of course, but they most often prove valuable for us.