Several blocks along the parade route, she embraced a tall woman weeping at the edge of the crowd who said, "Thank you."
"I haven't recognized them as equals," Vandyke said a few minutes later. "They have been invisible to me."
Later, parade Grand Marshal Dustin Lance Black, tweeted: "In tears. Over 300 straight, active Mormons showed up to march with me at the Utah Pride parade in support of LGBT people."
Mormons Building Bridges followed right behind Black in the parade. The men in beige suits and ties and the little girls in white dresses were a sharp contrast to the pounding music and dancers behind them, but the crowd clapped and shouted their approval for the folks in their Sunday best. Erika Munson, a mom of five from Sandy, started the group a few weeks ago to show her support for the LGBT community and to encourage members of her religion to do the same in a public way.
Holly Nelson, a 38-year-old lesbian who lives in Murray, had tears in their eyes as the Mormons walked past.
"I think it's amazing," she said. "It's been so hard to be in Utah knowing the Mormon church is against the gay community."
Seeing the group, which had three times the participants than originally expected, made her feel she isn't judged by every Mormon in the state, Nelson said.
The Church of Jesus Christ of Latter-day Saints does not consider same-sex attraction a sin, but sexual relations are only acceptable within the marriage of a man and a woman.
Some parade viewers talked about how their homosexuality had caused them to leave the church. How they might have remained members if the LDS faith were more tolerant.
Carolyn Ball, a 48-year-old lesbian from West Jordan, said she was excommunicated in 2000.
"I lost everything I loved because I came out," she said.
The marching Mormons included fathers carrying children on their shoulders and mothers pushing strollers, some of whom said they wanted to expose their families to this experience.
Nevin Munson, 13, carried a sign as he walked that said "Love thy neighbor as thyself."
"I'm very saddened by the amount of hate in the world," he said, describing the discrimination against gays and lesbians around the world. "I don't believe in that they're humans."
One man walking with the group reflected on a cluster of suicides in Mapleton when he was growing up. They were mostly teenagers and some were gay.
"There have been too many LDS deaths," said Adam Ford, 40, who now lives in Alpine. "No doctrine is more important than God's children."
Erika Munson, the Building Bridges founder, said afterward that the success of the event reflected the "deep wounds" in the community. She said organizers hope Sunday's event is the beginning of a grass roots movement.
"We want to inspire other Mormons at the local level to do things for their LGBT brothers and sisters," she said."What can you do in your area?"