Many of the Petroglyphs do not show up well in the thumbnails - take the time to bring up the large version of the photos to see some of the amazing details of these ancient pieces of art.

The photos are not necessarily in sequence with the discovery of the petroglyphs along the hike.

This geometric figure
is cut deeper into the rock than most of the petroglyphs, leading me
to question it's age - but
the city Rangers have it as a symbol on their Name Tags and consider it within the "historic" age.

In Pima Wash I was directed to look for these grinding holes near the geometric  Petroglyph above - they are much deeper than I expected.