We also have a state certification to work on lp gas, but doesn't have anything to do with air conditioning.
You're right.. it is for "gas" appliances. As part of the class they do cover sizing residential for air-conditioning. But it is for the furnace's as you mentioned.
I used to travel to Vernal once a month or so to take care of a few buildings years ago. I'm sure it's grown quite a bit since then. If you like the great outdoors, fishing and hunting and being out in the middle of nowhere then you would probably enjoy a place like Vernal. Flaming Gorge is a very popular spot for hooking some mighty big fish.