Yikáísdáhá, That Which Awaits the Dawn, is related to the annual Milky Way process. The emergence of pre-dawn is determined by the position of the Milky Way that changes with the nights, months and seasons.
Yikáísdáhá can be experienced by the full cyclical emergence of the Milky Way in the early pre-dawn hours of mid January. It is during this time the full circle of the Milky Way aligns with the horizon. Thus, a person can observe the full Milky Way in every direction, as it lays on the horizon in a circle. The Milky Way is depicted in Navajo sandpaintings as a crosshatched line, indicating the changes of its position in the night sky, from one side to another. Yikáísdáhá is the last of the eight main constellations and signifies completeness and wholeness.
Source: https://starlab.com/wp-content/uploads/2017/04/D.-10.-Navajo-Skies-v616.pdf