Black Elk was a Lakota holy man, whose story can be found in the book he created with John G. Neihardt, Black Elk Speaks.
In this image Black Elk can be seen sitting with his friend Standing Bear. The picture, of which this image is a part, was taken at the time John Neihardt was interviewing Black Elk, and can be found in Black Elk Speaks.
See, I fill this sacred pipe with the bark of the red willow; but before we smoke it, you must see how it is made and what it means. These four ribbons hanging here on the stem are the four quarters of the universe. The black one is for the west where the thunder beings live to send us rain; the white one for the north, whence comes the great white cleansing wind; the red one for the east, whence springs the light and where the morning star lives to give men wisdom; the yellow for the south, whence come the summer and the power to grow.
But these four spirits are only one Spirit after all, and this eagle feather here is for that One, which is like a father, and also it is for the thoughts of men that should rise high as eagles do. Is not the sky a father and the earth a mother, and are not all living things with feet or wings or roots their children? And this hide upon the mouthpiece here, which should be bison hide, is for the earth, from whence we came and at whose breast we suck as babies all our lives, along with all the animals and birds and trees and grasses.
Black Elk Speaks 1932, 1959, 1972 by John G. Neihardt, is published by the University of Nebraska Press.