Painted Cave Pictographs
We went to two sites that had some petroglyphs. They are not as notable, however as the Painted cave pictographs which is as hard to get to as it is sacred. You need 4x4, and also a chain saw for the shortest trail which I think was 12 miles with the return trip up hill. "Why the chain saw???", you ask. Well apparently trees get blown down all the time and land in the road. The trees are HUGE and you need a chain saw to cut through them to get home.
Another alternative is a longer trail with an overnight camp. In both cases you need to talk to the rangers at the visitor's center and get a permit.
Main Loop Trail Petroglyphs
It may have been the time of day and the lighting, but we found these petroglyphs to be very hard to see. Many of the petroglyphs are of faces (masks) which was something we had not seen a lot of in other places we visited so we enjoyed this a lot. The homes were occupied in the 13th and 14th centuries and this the petroglyphs are around 700-800 years old.
We purchased a booklet (about $3) called Long House and Its Rock Art in the visitor's center that helped identify the petroglyphs so we could see ones that we probably would have missed otherwise.
Tsankawi Trail Petroglyphs
The trail was well worth it without the petroglyphs so honestly the petroglyphs were the 'icing on the cake' as the saying goes.
There is a guide to go with the trail that was very useful in helping us identify locations for petroglyph. We bought this at the visitor's center in the main area of the park as there is no gift shop at this site.