I found a pretty good map that someone made that shows the airports that carry mogas.
http://www.chouby.com/apps/autogas.htmlIt appears that the criteria for appearing on the map is that an airport lists itself as having mogas on airnav.com. And, you're not going to like the complete absence of such airports in UT. Is anyone aware of deficiencies in this map?
It would seem that your next best bet is if someone posts about a strip where you can taxi across the street to a gas station. If you end up going west of SLC, then check out Delle, UT. There used to be some strips at 40.7625, -112.7872 next to the freeway where you could taxi up to a gas station. Does anyone know the name of the gas station or if they have ethanol in their fuel?