Undie Run organizer Nate Porter says the goal of the event Saturday was to organize people frustrated by the conservative nature of the state's politics.
Nudity was prohibited by organizers. Participants donned bras, panties, nightgowns, swimwear or colorful boxer shorts - and some added political messages by expressing support for causes like gay marriage on their chests, backs or legs.
Salt Lake City is the home of the Mormon church, which is a vocal opponent of gay marriage.
Porter estimates 3,000 people participated in the run, which began in downtown Salt Lake City and circled past the state Capitol building about a mile away.