sign, caution, do not cross. grand canyon usa

adventure alertness arizona background barrier billboard boulder canyon cliff climbing close colorado concept copy countryside danger dangerous desert dirt effect exploration extreme falling famous footpath formation frame geological gorge grand hazard high hiking horizontal informationssign mountain nature nobody overcast overlook pass pathway peak photography placard place plateau point post ravine reserve risk river rock rocks rural safety sandstone security shield sightseeing sign space terrain texture top tourism touristic trail trekking trip usa vacations viewpoint warning watch wilderness yellow