The parade welcomes a variety of other groups that advocate for causes, she said, including The Church of Jesus Christ of Latter-day Saints.
Smith did not return a call Friday seeking comment.
Munson said she suspects the Days of '47 committee fears that allowing Bridges into the parade would open the door to other "special interest groups," with politically driven messages or goals.
But that's not her group's goal. "Our desire is to include the whole community in this big, wonderful celebration," Munson explained. "And it's incredibly appropriate for LGBTQ Utahns to be represented in a pioneer parade, because they are pioneers."
The July parade is the focal point of Pioneer Day, the state holiday honoring the arrival of Mormon settlers in the Salt Lake Valley in 1847.
Run by a private nonprofit, the event is Utah's largest parade.
Hundreds of Bridges members march in the second largest: the Utah Pride Parade, which anchors the annual June celebration of the state's LGBTQ community.
For its Days of '47 entry, Bridges had proposed a float depicting southern Utah's Rainbow Bridge. It would have included a banner citing the 2017 parade theme, "Pioneers: Visions of a New Horizon," and eight riders, each a member of Utah's LGBTQ community.
Munson said her group will continue to apply for a parade slot and hopes to be able to sit down with organizers to talk.
"We have tried and tried and tried," she said, "and that hasn't happened."
Munson also hopes other Mormons will join Bridges in advocating for community inclusion — a position she sees as consistent with the LDS Church's public pronouncements.
"Messages of family inclusion and general inclusion and love in the public square," she noted, "are coming from the church all of the time."
The positions held by Days of '47 officials seem inconsistent with that, Munson added, even though they may believe they are upholding Mormon standards.