Yes, it's a beehive, which is the official emblem of the state of Utah (seehttp://www.50states.com/bio/nickname5.htm ). Most states have an official emblem, flower, bird, etc. The beehive sign designates this road as state highway #279. A shortened version would be "SR 279" ("SR" = "state route"). State highways are maintained and controlled by the state: repairs, signage and regulations. Highway 191 (another gallery) is marked with such signs.
Other signs here tell people that the general direction of travel is to the south, that this road has been designated (by the state, I think) as a route of natural beauty that is not a main road, and that fireworks are not allowed in this travel corridor (to minimize the risk of fires and to keep noise at a minimum). The big yellow sign does not refer to 279, but to the dirt roads that branch off of it. Potash Road, 16 miles ahead, is one of those roads.