Any no gun sign in New Mexico is enforceable. Any Restaurant that serves drinks is off limits... The usual federal buildings and post offices are the same as Texas so no big deal there..
I was traveling in our motor coach, solo, and found that the map app on my phone was not really good enough for driving a 44 foot coach around on unfamiliar streets. I decided to buy a GPS more suitable and stopped in at the Roswell Walmart... You could have knocked me over with a feather when I saw the small 8 x 10 sign with red letters "NO GUNS" posted on the front door.
After reading it twice to make sure, 
I did an about face and drove away. They lost about 700.00 in sales that day.Once I arrived in Ruidoso I stopped by the local Walmart and found they also had the same sign on the front door... They lost about 1000.00 in sales from me that day.
I thought Walmart was a great store. In New Mexico they are not! The Target store in Roswell was not posted and gladly took my money, thanked me for shopping with them and bid me safe travels.. Walmart would not even let me in the door...
So far today I should have just left my weapon in the motor coach safe. Lunch was a great little Mexican food restaurant that did not served alcohol.
Problem was they are right smack in the middle of the Indian Reservation where I can't carry.. 
.... My brother needed some items so, of course, drove to Walmart, where I sat in the truck. 
Dinner was at a hamburger place where they served drinks so the holster came back off and stayed in the truck. New Mexico needs to take lessons from Texas where the 30.06, 30.07 and 51% signs are in use. While not perfect they sure beat the heck out of New Mexico's system.
Friday I cross the line back into Texas and I'm sitting here counting the minutes!