The man to the left is my grandfather, George Buffalo Sr. and to the right is James Ward. Both men are of the Meskwaki tribe in Tama, Iowa. Photographs of the "Tama Indians" were often taken during the annual pow-wow and made into postcards for resale. I'd date this photo at about 1918 - 1919 judging by my grandfather's approximate age here. Their dress is traditional Meskwaki except for the headdresses, which were gifts and of Siouan origin.
I would love to see more of the photos in your collection. I'm sure the Meskwaki Historical Preservation Department would appreciate high quality scans of your collection.

Contact:
Mary Young Bear at 641-484-3185
http://www.meskwaki.org/Historical%20Preservation.html

[You can try contacting the member directly by clicking on the member name (after "Submitted by" above the photo) and then the Contact tab on their profile. -tterrace]

There was a line of "Realphoto" postcards in the early 20th century which were actual emulsion prints, albeit black and white. They scan much better than halftone or hand-colored postcards, with real detail, like the magnificent picture here. This could be such a card, or a similar competitor. The car appears to be 1915-1920 vintage. The ceremonial outfits display excellent floral pattern beadwork or quillwork typical of the midwestern tribes and the Great Lakes region, quite a contrast to the more geometric patterns of the Plains cultures. I would certainly like to see more!