I like the Public Access Utah sticker idea the best. It give a good connotation that all of Utah is for all the people to access.
A note on Cryptobiotic soil. We have friends that have property about 10 miles south of Moab above where Behind the Rocks comes out and they have crypto soil everywhere. The kids have ran all over that place playing paint ball and what not and every spring you could not even tell that anyone had stepped on the crypto. You could see indentations in the soil but the crypto had covered it like a blanket. Common sense says stay on the trails when ever possible and not to tear up the place with tracks and unneeded trails (by bike, foot or motor).
Here is a portion of the Wikipedia the Greg posted that tell the growth, it also stats that fire can do more severe damage than people can.
http://en.wikipedia.org/wiki/Soil_crust "Full recovery of crusts from disturbances is a slow process, particularly for mosses and lichens. There are means to facilitate recovery. Allowing the cyanobacterial and green algae component to recover will give the appearance of a healthy crust. This visual recovery can be complete in as little as 1 to 5 years given average climate conditions. However, crust thickness can take up to 50 years, and mosses and lichens can take up to 250 years to recover. Limiting the size of the disturbed area also increases the rate of recovery, provided that there is a nearby source of inoculum."