petroglyphs

a palimpsest of petroglyphs --- in the center, barely visible, are thousand-yr-old anasazi images, to the right post-contact hopi, and to the left 19th c navajo

antiquities thieves can saw out these things to sell on the black market  --- these are 20 feet above the canyon floor, but many are not -- theft of resources is one reason national parks should not be open with absolutely no protection