May is pretty early- normally. You may be alright this year as it has been a very light snow year. Likely still be some higher areas you can't get access but there will be tons of great riding!
As stated- be prepared for anything especially at the higher elevations. In late June of last year we had a storm come over and dump 3" of snow on us in 40 minutes- we were at 10k feet. An hour later we were back in Marysvale where it was sunny and 80 degrees.
In Utah I always pack a tarp and parachute cord along with all of the other stuff we always have in the UTV. When the weather turns ugly- which is never for very long- A tarp tied between the UTV and a tree or simply thrown over the top of the UTV and bunggied down makes for a much warmer and drier place to wait out an afternoon storm.