Booths hosting games of tug-of-war, Limbo, Bags, and mini-golf lined the grass of Hubbard Park on Sunday.

As part of the 33rd-annual RiverFest — a celebration of everything that is Iowa City — community members and students gathered for the 10,000 Hours-hosted carnival. Officials held the carnival to reward volunteers.

"There’s a tough economy, there’s pressure to get higher GPAs, a job, and it’s hard to get yourself involved," said Molly McDonnell, the executive director of the 10,000 Hours Show. "We want to reward the students that do."

This year marks the first time the 10,000 Hours Show has hosted the carnival. In the past, it had been strictly a RiverFest event.

The 10,000 Hours Show coordinators invited University of Iowa student organizations to set up at the carnival as a way to increase and promote student involvement in those organizations.

Madeleine Stroth, the president of the UI Panhellenic Council, said she especially supported the collaboration.

"It’s an opportunity to get involved with other student organizations and help other student organizations out," she said.

The lure of free cotton candy and a carnival in Hubbard Park enticed Lance Secrest, 44, and his family to change their lazy Sunday plans.

"The kids were bored, and we were just walking downtown when two girls with cotton candy told us about the carnival," the Iowa City resident said.

Face-to-face interaction, promotional e-mails, and social media were the keys in promoting the first carnival, said Katie McDonnell, the director of public relations and marketing for the 10,000 Hours Show.

The carnival wasn’t the only RiverFest-related event Sunday.

Over 1,000 people particpated in the RiverRun, which included a 5K run/walk/wheelchair and 10K run/wheelchair event. Proceeds from the race benefit Uptown Bill’s Small Mall of Iowa City, a collection of businesses owned and operated by people with disabilities and staffed by volunteers.

"The streets and the trails are very scenic," he said. "It’s flat, it’s fast, and it’s good for running, and Iowa City takes advantage of that. It’s a very nice place to run."

RiverRun and RiverFest began as the same organization, but recently split due to RiverRun’s popularity, said Marissa Paulsen, the executive director of RiverFest.

RiverFest, which has hosted 19 events since April 11, is a way to bring the community together, as most of the events are free, said Melanie Nelson, the public-relations director for RiverFest.

"It’s to highlight all of the things that make Iowa city a unique and interesting place to live," she said. "Because we have that balance of the big-town school with the small-town atmosphere."