Cavalrymen from the Utah National Guard skirmished with Mexican forces along the Arizona border, resulting in ten Mexican casualties. This was the third, and last, skirmish that the Utah National Guard would engage in during the Punitive Expedition.
This unit would have been the 2nd Utah Cavalry, which remained on the border until March when relieved by the Regular Army's 10th Cavalry.
Note: An item posted on Reddit's 100 Years Ago subreddit from the New York Times reports that this incident started off with cowboys trying to drive cattle away from the border at which time they were fired upon by "Mexican Troopers".
It's unclear in whose service the troopers were, but this gives a new dimension to the story.