"Anasazi" actually means "ancient enemies" or "ancestors of my enemies." (In fact, many names of Indian tribes are a neighboring tribe's word for "enemy.") This may not be a Goof, because the Indian guide may have intentionally misled Dr Hazlett.
Although there have been innumerable instances throughout history of casting non-indigenous actors in indigenous roles, guest star Randolph Mantooth (Raymond Two Crows) is half-indigenous/half-European. Specifically, Randolph is Seminole, Cherokee, Potawatomi, Scottish and German. Ironically, at one point in the story, Jessica (Angela Lansbury) and Seth (William Windom) discover that "Raymond Two Crows" was actually "Raymond DeMarco", and not necessarily indigenous at all.
The dog tags William Windom's character wears are his from when he served in WWII.