Las Cruces is a major city. Las Cruces/El Paso/Juarez together comprise a metro area nearing 2 million people.
Dripping Springs Road/University Ave exit is off of I-25 very near the I-25/I-10 interchange south of Las Cruces (about 35 miles N of the main part of El Paso).
Regarding the geology, I can only speak in general terms. It's obvious a volcanic range (as opposed to sedimentary). I doubt it was once a volcano though. Likelier the result of uplifting and other ancillary acts of volcanism.
"Got tight last night on absinthe and did knife tricks. Great success shooting the knife into the piano. The woodworms are so bad and eat hell out of all furniture that you can always claim the woodworms did it."