The photo I used for reference is one of my favorites from Ed Curtis. It's from 1904 and shows a Navajo warrior: http://curtis.library.northwestern.edu/curtis/viewPage.cgi?id=nai.01.port.00000027.p&volume=1&showp=1&size=3#nai.01.port.00000027.p
This is Curtis' comment to his photo: "Picturing not only the individual but a characteristic member of the tribe - disdainful, energetic, self-reliant."
Drawn with Corel Photopaint using a tablet.