If it's specifically about Geronimo, how about calling him Apache? Calling him a Native American is about as meaningful as calling Julius Caesar (or Boadicea!) a Native Eurasian, don't you think? You might also call him, at least parenthetically, by his proper name, Goyathlay. (As Crazy Horse really ought to be called Taśunka Witco, Chief Joseph — Hinmatuyalatkeht, Chief Seattle — si?aL, etc.

Haruo