The "dunes" look like sand but are actually a soft crumbly clay-like rock.
mixed with hard rock
the main objective of our day hike was to see these petroglyphs (click on picture to wander around a larger image of the rock art). There is evidence of human history in the area for more than 10,000 years. Pictographs and petroglyphs disappear over time and most are much more recent, roughly in A.D. 300 - 1900 range, depending on where you are and what you are looking at.
catching my breath, or pausing for another landscape picture?
Ranger making sure he isn't leaving any fossils behind...
looking down at several petrified logs, one has been undercut and now forms what they call an agate bridge (since the log is now quartz agate). As an aside, there was once logging done of the petrified logs, since they could be ground up to make good abrasives. That was one of the factors in putting aside part of this area in 1906 as a National Monument to preserve for future generations to enjoy. [biting tongue to avoid inserting modern day political commentary here... *smile*]