When I first retired I attended an Elderhostel session in Taos, New Mexico. When talk turned to books, several people mentioned Hillerman, so I tried him and was hooked. I think I have read all his books, even the ones not set in Navajo country. The books feature two tribal detectives, Leaphorn and Chee. Leaphorn is the modern man (or tries to be) -- educated, skeptical. Chee is softer, something of a mystic. Many of the crimes they solve require understanding of Navajo ways. (That's when the FBI messes up.)
The Thief of Time is probably the best of them, but they all give a picture of Indian country, its landscape and people.