Taking its name from one of the longest living trees in the Arizona desert, the 129,000-acre Ironwood Forest National Monument is a true Sonoran Desert showcase. Keeping company with the ironwood trees are mesquite, palo verde, creosote, and saguaro – blanketing the monument floor beneath rugged mountain ranges named Silver Bell, Waterman and Sawtooth. The national monument also contains habitat for the cactus ferruginous pygmy owl and desert bighorn sheep. Photo by Bob Wick. Posted on Tumblr by the US Department of the Interior, 3/24/17.