They have not released the name of their church in order to protect themselves and other members of the church, but they do live in an area that is highly populated by members of the Apostolic United Bretheren, a polygamist sect with an estimated 7,000 members. Locals refer to the church as "The Allred Group". From what I have seen on the show, all evidence points to them belonging to this group.
Please note that this group broke from the FLDS (whom you might recognize from the Texas raids in 2008) in the early 1950's. The FLDS broke from the mainstream LDS or "Mormon" church in 1890. Because of this, the Brown family featured on "Sister Wives" has many beliefs similar to those of Mormons. In fact, Kody and Janelle both grew up in the mainstream Mormon church and converted to their current religion after graduating high school.
Sister Wives - 2010 Sister Wives Tell All was released on: USA: 22 September 2013
Sister Wives was created on 2010-09-26.
Sister Wives - 2010 Wives on the Move - 1.3 was released on: USA: 3 October 2010
Sister Wives - 2010 Polygamy Questions Answered - 6.7 was released on: USA: September 2013
New episodes of Sister Wives will start airing in May 2013.
Sister Wives - 2010 Sister Wives Separated was released on: USA: 13 May 2012
Sister Wives - 2010 Sister Wives Tell All was released on: USA: 22 September 2013
Sister Wives - 2010 Sister Wives on the Strip 2-22 was released on: USA: 20 November 2011
Yes, Sister Wives was on the air in 2013.
Sister Wives was created on 2010-09-26.
Sister Wives - 2010 Sister Wives in the City of Sin 2-11 was released on: USA: 5 June 2011
Yes, Sister Wives will be returning.
Sister Wives - 2010 Wives on the Move - 1.3 was released on: USA: 3 October 2010
bcause they get bord with the wives and want to get it in with the exrtremly hot sister .
Sister Wives - 2010 Polygamy Questions Answered - 6.7 was released on: USA: September 2013
New episodes of Sister Wives will start airing in May 2013.
Sister Wives - 2010 4 Wives 4 Valentines was released on: USA: 3 June 2012