You have noticed that everything an Indian does is in a circle, and that is because the Power of the World always works in circles, and everything tries to be round.
Everything the Power of the World does is done in a circle. The sky is round and I have heard that the earth is round like a ball and so are all the stars. The wind, in its greatest power whirls. Birds make their nests in circles, for theirs is the same religion as ours. The sun comes forth and goes down again in a circle. The moon does the same and both are round.
Even the seasons form a great circle in their changing, and always come back again to where they were. The life of man is a circle from childhood to childhood and so it is in everything where power moves. Our tipis were round like the nests of birds and these were always set in a circle, the nations hoop, the nest of many nests where the Great Spirit meant for us to hatch our children.
Excerpt from ʻTouch the Earth, A Self-Portrait of Indian Existenceʼ