Participants from Utah, Arizona, Idaho and elsewhere gathered in a public park to sign a "Declaration of Independence from Mormonism."

"This feels awesome," said Alison Lucas, from West Jordan, Utah, who took part in the rally amid soaring temperatures. "I don't know if I would have had the courage except in a group."

The Utah-based Church of Jesus Christ of Latter-day Saints is known for its culture of obedience, and the mass ceremony was a seldom-seen act of collective revolt.

After gathering in the park, participants hiked a half-mile up nearby Ensign Peak, scaled in 1847 by church President Brigham Young to survey the spot where his Latter-day Saints would build a city.