War Dance:
It is quite likely that Alfred Miller never saw an Indian battle, but he no doubt heard tales of such warfare from the mountaineers around him. He may have witnessed the prowess of horseback riding demonstrated in this painting since the braves at rendezvous seldom shied from showing off their equestrian abilities. Mock skirmishes were also commonly re-enacted at these summer gatherings.
At the 1834 rendezvous on Ham’s Fork of Green River, William Marshall Anderson described a mock war dance held in the camp of Tom Fitzpatrick. The principal actor in the display was Jean Baptiste Charbonneau, son of Toussaint Charbonneau and Sacagawea, noted members of the Lewis and Clark Expedition.
Trapper Warren Ferris provided a description of one such demonstration:
War dances are usually held in the evening, round a large fire, made for the purpose; … youths and warriors jump into the ring, and dance with vigor, keeping time with the drum, yelling at intervals like demons, shaking aloft their gory gleanings of a field of carnage, (scalps, etc.) flourishing their weapons in their rapid evolutions, throwing their bodies into unnatural, sometimes ludicrous attitudes, and chanting aloud their deeds of desperate daring.
Horsemanship:
Artist George Catlin painted a similar image when he accompanied the United States Dragoons into Indian Territory, three years before Miller’s westward adventure. In his notes, Catlin wrote:
Amongst their feats of riding, there is one that has astonished me more than anything of the kind I have ever seen, or expect to see, in my life:—a stratagem of war, learned and practiced by every young man in the tribe; by which he is able to drop his body upon the side of his horse at the instant he is passing, effectually screened from his enemies’ weapons as he lays in a horizontal position behind the body of his horse, with his heel hanging over the horses' back; by which he has the power of throwing himself up again, and changing to the other side of the horse if necessary. In this wonderful condition, he will hang whilst his horse is at fullest speed, carrying with him his bow and his shield, and also his long lance of fourteen feet in length, all or either of which he will wield upon his enemy as he passes; rising and throwing his arrows over the horse's back, or with equal ease and equal success under the horse's neck.
Jim Hardee
Further Reading:
Anderson, William, The Rocky Mountain Journals of William Marshall Anderson
Catlin, George, Letters and Notes on the Manners, Customs, and Conditions of the North American Indians
Ferris, Warren, Life in the Rocky Mountains