The State's raid on the polygamist compound in Eldorado has caught the attention of Congress.
The Senate Judiciary Committee plans to hold a hearing next week.
It will focus on coordinating a State and Federal response to Polygamy.
Senator Harry Reid of Nevada called for federal intervention after the raid at the Yearning for Zion Ranch in April.
Spokesman Willie Jessop for the polygamist group says he's outraged that only critics of the sect have been asked to appear.
He says church representatives plan to show up anyway.
More than 400 children were removed from the Polygamist ranch, after concerns surfaced about possible abuse.
The youngsters were later returned to their parents after a State Supreme Court decision.