Bruce Brown's 100 Voices...
Ohiyesa's Story of Crazy Horse
ANOTHER STORY told of [Crazy Horse's] boyhood is that when he was about twelve he went to look for the ponies with his little brother [Little Hawk], whom he loved much, and took a great deal of pains to teach what he had already learned. They came to some wild cherry trees full of ripe fruit, and while they were enjoying it, the brothers were startled by the growl and sudden rush of a bear. Young Crazy Horse pushed his brother up into the nearest tree and himself sprang upon the back of one of the horses, which was frightened and ran some distance before he could control him. As soon as he could, however, he turned him about and came back, yelling and swinging his lariat over his head. The bear at first showed fight but finally turned and ran. The old man who told me this story added that young as he was, he had some power, so that even a grizzly did not care to tackle him. I believe it is a fact that a silver-tip will dare anything except a bell or a lasso line, so that accidentally the boy had hit upon the very thing which would drive him off.
Indian Heroes and Great Chieftains by Charles A. Eastman (Ohiyesa), Little, Brown, and Co., Boston, MA 1926.
A full-blooded Santee Sioux who graduated from Dartmouth College and Medical School, Dr. Charles Eastman or Ohiyesa was subsequently hired by the Indian Medical Service and arrived on the Pine Ridge Reservation just in time to treat the wounded survivors of the Wounded Knee Massacre in 1890.
Although he was not at the Battle of the Little Bighorn, he (like the other Indian chroniclers in Astonisher.com's 100 Voices -- John Stands In Timber, William Bordeaux, Pretty Shield, David Humphreys Miller and George Bird Grinnell) had intimate access to numerous Indians who were there, and learned their accounts first hand.
There is probably no one else who could have gotten death bed access to Rain In The Face as Ohiyesa did, and even more certainly no one who could have written the old warrior's story better.