The Yei symbol represents the Navajo Yei Spirit who mediates between humans and the Great Spirit. The term Yei derives from the word Yeibichei meaning the “Holy People.” Depictions of Yei were commonly created on Petroglyphs and Sand Paintings, in order to enlist their aid. Yei spirits were believed to control natural elements such as the rain, snow, wind, and sun and to have healing powers.