Marc Simmons, New Mexico historian.

His "Trail Dust" column in the Santa Fe New Mexican is the main reason to read that paper other than the often amusing Letters to the Editor. (Don't even try a search at the paper's online version, it's terrible. Abandon hope all ye who enter there. )

If you are interested in the history of New Mexico, there is absolutely no better writer and no more impressive authority than Mr. Simmons. I envy your discovering him for the first time.