Polygamy laws are largely unenforced. If they were, strictly, the poly people would probably be in violation, too. They'd go to court and get it declared legal. Kind of like sodomy laws were for a long time before officially getting overturned, the only time someone tries to enforce them is when they have some agenda. Those Colorado City people shit on the government in general, which is what really got them into trouble. They defy government while also collecting welfare checks. You might have a problem if you try to take out two different marriage licenses at the same time, as an issue of fraud, but just telling people you're plural married won't get you in trouble, even though that's similarly illegal -- as far as I know.