When I was in High School, last 2 years in Utah, I ran into a lot of Navajo speakers. Some of the kids my age spoke Navajo more than English. I was on the wrestling team and we had a meet at the Intermountain Indian School the coach gave his wrestlers instructions in Navajo. What he did not know was that we have a couple of Navajos on our team and they quietly translated for us. That code talk didn't work so well.
There used to be a Navajo language radio station in Southern Utah, maybe still is.