This view is entering Northumberland Canyon from Monitor Valley, Nevada.  A number of rhyolite outcroppings off the forest service road have many etchings within the rock that appear as petroglyphs, though I don't think most are prehistoric as they don't look weathered.  It is odd as they appeared unexpectedly & if they are recent then some individuals had some time on their hands.  This panel shows a number of handprints & other designs - the handprints are bigger than my hands.  The area has been known to miners back to the mid-1800s.