Cleaning sometimes involves heavy lifting, but volunteers for the second annual Platte River Revival likely had no idea what they were getting into.

More than 400 people spent their Saturday morning planting trees, recycling bottles, tossing trash - and helping to lift six cars out of the river in Casper.

One car was removed Friday, said Cynthia Langston, solid waste manager for the city, and more large objects will be removed with heavy equipment at a later date.

City officials found the larger objects in need of removal during a helicopter fly-over of the area. A photographer and global positioning system helped pinpoint exact locations, and officials floated the river to find further pollution.

On Saturday, an in-river team helped to identify and collect debris and large objects on the floor of the Platte.

"The water is low - that's why we do it now," Langston said. "We get into the river when it's low and we can see."

Along 13 to 15 miles of the river banks, volunteers removed noxious weeds and trees. Russian olive trees were most in need of removal, and for each tree removed, another one or two trees native to the area were planted.

With a black plastic garbage bag and a knife, Jim Gerhart, an arborist for the city parks division removed a deflated inner tube from underneath a rock by the riverside.

In addition to piles of tree limbs and weeds, Gerhart's team found an oar, fully intact, but "nothing too out of the ordinary."

The team planted trees and collected trash along the river near Jonah Bank.

"I just think it's a great thing," Casper resident and volunteer Karen Zaback said of the Revival. "It's a beautiful river."

Volunteer Heather Fransted agreed, adding that she enjoys a view of the Platte River every day from the windows of the bank.

"Jonah Bank's motto is 'building a better Wyoming' and this does that. It makes the community better," said Stacy Rosenbaum, who also works at the bank.

Two Fly, an area fishermen's club, initiated the cleanup "because they fish here and they know what a jewel the river is to the community," Langston said. The club, along with the city's "Keep Casper Beautiful" program, spearheaded the event.

Boats, kayaks and canoes float down the river regularly, she said, and large debris is bad not only for recreational activities, but also for the environment.

"We hope this is a project that will continue in the future for future generations," Langston said.

Contact reporter Megan Lee at (307) 266-0616 or megan.lee@trib.com