Have you ever met a mormon with more than one wife? If you have then they aren't mormon.
Not a legal mormon.
I'm sure there are some mormon minorities who still practice polygamy, but they wouldn't be wise to let anyone else know, since it is illegal.
But not unheard of. The TLC programme,
Sister Wives documented the life of a Mormon polygamist family.
While the father argued he was only legally married to 1 person and therefore not breaking the law, they did live for all intents and purposes as a polygamist family.
And I highly doubt they're the only ones to do so.
Polygamy has been illegal since 1862, and was fully accepted by the Mormon church in 1890, and then in 1904 was further extended to cease any polygamist marriages that still existed.