From this story in the Casper Star-Tribune:
Gov. Matt Mead signed a bill into law that will allow the use silencers on firearms for all types of hunting. Mead signed the bill on Monday and the law will go into effect in July. The federal government regulates silencers and 39 states allow civilian ownership of them. Wyoming will join 27 other states that allow their use for hunting. The American Silencer Association has been pushing legislation in several states this year to allow using silencers for hunting. The Wyoming Game Wardens Association had opposed the bill, saying silencers could help poachers and would give hunters an unsporting advantage over game.