Here's a correction on my estimate: The Dragoons are 25 miles long. This site gives a nice overview of the geology:
http://skywalker.cochise.edu/wellerr/students/dragoons/mark_alexander_geology_web_page.htm

I drove the horses this morning again, heading for a time towards the Dragoons. I was struck by how little this area has changed. Yes, there is a scattering of houses, scraped roads and occasional fence, but the land and the vegetation looks unchanged. This isn't a place where land gets plowed. There is some cattle grazing, but the landscape is still mesquite and yucca. The mountains, thankfully, don't have towers on top. It is easy to image Apaches behind bushes or laying in the grass. Driving along I picture they would wait till the coach passed and attack from behind (unlike stagecoach robbers in the movies). That way they would have a chance to shoot without counterattack.
Driving along the south wind blew my brim hat back on its chin string, again, an image from the movies.
I'll add some pictures of my horses from yesterday, taken by a neighbor.