Here's an image of two Pawnee Scouts, La-Roo-Rut-Ka-Haw La-Shar (Night Chief) and La-Roo-Ra-Shar-Roo-Cosh (A Man That Left His Enemy Lying in the Water):
CDV of <i>La-roo-rut-ka-haw La-shar</i> (Night Chief) and <i>La-roo-ra-shar-roo-cosh</i> (Man That Left His Enemy Lying in the Water), Pawnee, - Cowan's Auctions
More textual information at the bottom, if you scroll down.
Here's a rather clearer print someone's put-on flicker:
Pawnee Scouts | Flickr - Photo Sharing!
If these men were working for the U.S. Army they would have been getting some flour, sugar, and coffee, but they've obviously not run to fat!
This is what someone capable of killing large game with a stone projectile point, of covering the vast distances on the Plains on horseback (and sometimes on foot), and of making himself comfortable with a modicum of clothing and shelter in temperatures that caused white men to get frostbite looks like. As a reminder of how violent life on the Plains could be -- in 1873, while Pawnee men were hunting buffalo in the Republican valley, some Sioux caught a moving column of their unprotected women and children and killed 150 of them. So here's something else one had to ready for living in that environment: sudden and bloody combat with hand-to-hand weapons. (The U.S. Government was, of course, able to use a policy of divide et impera to exploit the enmities of North American Indian tribes.)
George Bird Grinnell's account of Frank and Luther North and the Pawnee Battalion has much interesting contemporary information. Grinnell himself writes of having seen a Pawnee shoot an arrow clean through a buffalo. The distances these men were able to run are also remarkable. Sure, long-distance running is not a healthy thing for anyone to do, but it's interesting that people living this life could do it when the need was there. Interestingly, they seem to have done it on little water, too, something that's not recommended these days and that most people would probably do well not to try. There's an account of a foot-race between two Pawnee and the one who loses seems to have lost because he drank too much water, thereby making himself sick; the other only took a mouthful or two and used the rest to cool his head.
Amazon.com: Two Great Scouts and Their Pawnee Battalion: The Experiences of Frank J. North and Luther H. North, Pioneers in the Great West, 1856-1882, and Their D (Bison Book) (9780803257757): George Bird Grinnell, James T. King: Books