Sloan Petroglyph Site

The Sloan Petroglyph Site was added to the National Register of Historic Places (#78001720) on December 19, 1978.

From Wikipedia:
Sloan Canyon contains a great many petroglyphs and has been called the Sistine Chapel of Native American rock art due to their size and significance. Archaeologists believe the more than 300 rock art panels with 1,700 individual design elements were created by native cultures from the Archaic to historic eras.