Native Americans trod the Land of Secrets thousands of years before latecomer European Americans discovered it. They left tell-tale signs of their occupation. One of those signs of occupation is rock art in the form of petroglyphs and pictographs.
A petroglyph is made by chipping into the rock itself to expose lighter colored material below. Varnish covered rock faces are prized locations for creating petroglyphs. Pictographs, on the other hand, are paintings on a rock surface that are made by mixing local pigments or painted with charcoal.