JOEL - No one anywhere in the United States can legally marry more than one woman, including Utah. Please remember that there is a difference between the Mormons (not "mormans"), who are members of the Church of Jesus Christ of Latter-day Saints, and the many polygamist groups that can be found in various parts of the country, some of which are in Utah. Some of those groups had their roots in Mormonism, but are now in no way affiliated with the Church of Jesus Christ of Latter-day Saints.
Actually, most of those polygamists are only "legally" married to one woman, as far as the law is concerned; meaning they have only one marriage certificate showing they are married to only one person. However, they do perform their own marriages to additional women within their own religious sect, but there are no marriage licenses obtained, nor it is ever recorded in the county records. Therefore, the only thing that they could be arrested for, as far as the law is concerned, is illegal cohabitation, which a lot of other people do anyway without calling it marriage.