Chaco Canyon: Navajo people probably scratched this horse-and-rider petroglyph into the rock sometime after the 16th century when horses were first brought by the Spaniards to the southwest.

Navajo people probably scratched this horse-and-rider petroglyph into the rock sometime after the 16th century when horses were first brought by the Spaniards to the southwest. ; Petroglyphs found on the cliff face between Chetro Ketl and Pueblo Bonito. These images were probably meant as visual communication: clan symbols, records of migration events, and memory aids for recalling stories, songs, and ceremonies. Most of the Chaco panels are closely associated with buildings and can be dated to when the buildings were in use (ca.850 to 1250).