This image was taken by John H. C. Grabill in 1981 and it is a picture of 2 Sioux indians called Red Cloud and American Horse. I have chosen this image as it is showing the 2 indians in 2 comepletely different dresses with one being in their native wear such as the head dress and feathers with the other in a very Americanised dress such as the cowboy hat, jacket and he even has a pistol in a holster around his waist. I find the gun very interesting as it is rare to see any native peoples in photos or images depicted as having a weapon like this. They also seem to be shaking hands in front of a wigwam, which could be their camp, as if they are coming to some sort of agreement. It could be that maybe they are from 2 different Sioux language groups as the website goes on to say that they split in to 3 formidable groupings called the Santee, Yankton, and Teton Sioux. It was from these groups that the Teton Sioux, Cheyenne, and Arapaho native peoples defeated General Custer at the Battle of the Little Big Horn in 1876.

http://international.loc.gov/intldl/mtfhtml/mfcolony/igcsioux.html