The Rings Trail loop at Hole in the Wall in Mojave National Preserve (CA) begins at the far end of the visitor center parking area. About a quarter mile into the hike, you will see a large boulder next to the trail which has a number of petroglyphs on it:
I always get confused what to call these when I see them (petroglyphs or pictograms), so I had to finally took the time to figure out the difference between the two. Petroglyphs (often times referred to as rock engravings) are created by removing part of a rock surface to make the picture or symbol. Pictographs are images drawn or painted on a rock face rather than engraved into it.
While the petroglyphs at Hole in the Wall aren’t the best examples to see at National Parks (they are fully accessible and it appears that people have touched them over the years), they are still worth stopping for and admiring on your hike.