It's hard to say what the first Native-themed movie was. The offerings ranged from shorts of one or two reels to full-length films. There were documentaries, dramatizations, and feature films. Domestic- and foreign-made films.
And of course many of them haven't survived. So we don't know exactly what they were.
But there were a smattering of films from 1898 to 1908. Then came "The Deluge--1909-1914."
It started with perhaps 50 Native-themed films in 1909. Then:
In 1911 close to 200 Indian pictures were released.
In 1912 production of Indian films was down to approximately 150.
In 1913 studios released over 100 Indian films.
In 1914 the Great War started in Europe....Criticism of Westerns had been building and, by now, everyone said they were out of style. Yet close to 150 Indian films were made during this year.
The 1910 list included movies ostensibly featuring Apache, Arapaho, Cheyenne, Sioux, Iroquois, Navajo, Zuni, Seminole, and Ute Indians. Which is about eight or nine more tribes than you'll see in mainstream Hollywood movies in 2015.