I don't do this lightly.

There are these videos on you tube that express the Spirit of a Sundance.

These videos are Shoshone and I am assuming this was all done legit
and that this Sundance was recorded with permission.
Ceremonial things are not usually allowed to be recorded.
I only bring your attention to it because it is already public.
As I said it expresses the Spirit of the Sundance and of course I do not
imply that all Sundances are carried out in this manner.

The videos are broke up in 6 parts about 10 min. each.

1.https://www.youtube.com/watch?v=DAjw0Z_83jY

2.https://www.youtube.com/watch?v=jGgziPvWQCE

3.https://www.youtube.com/watch?v=cBwIzleWnGs

Video 4, 5 and 6 are titled
Sun Dance Part 2 1/3
Sun Dance Part 2 2/3
Sun Dance Part 2 3/3