According to the city stats Gallup has just over 70k including the "metro" area, Alamogordo has 30k total.
No way Gallup NM is anywhere close to 70k and there is no 'metro' area. I'm pretty sure.
Just posting what the official population stats are.

Just checked a couple of other population reporting sites and they all state 20k so the one site I was using looks to be wrong.
Apparently so. When we were still working we would be in Gallup at least once a month and sometimes more, plus we go through there on our way to work in Arizona, gamble in Laughlin, or visit in California. And we would be in Alamogordo as frequently and often overnighted there or in Cruces.
Alamogordo is heavily Hispanic, a military town with Holloman AFB nearby, the Space museum is there and the Space Port, plus many points of interest within easy day trips. A neat little town but not at all cosmopolitan. You would have to like small towns to like it there.
Gallup is at least 75% Native American and Hispanic population with the Navajo plus a few Hopi being the largest demographic group. As such there is a very definite cultural and historic feel to the town and you feel like you're in the middle of the old wild west. But there isn't much to do there and it isn't close to anywhere.