It's something no one wants to see in the beauty of nature, litter.
"We also noticed a lot of debris in the waters and the little eddies of the water that doesn't flow," Larry Brightwell said.
Cleaning up the parks along the Big Sioux River, it's what the city of Sioux Falls is asking you to do this weekend.
"All we really need is people to show up at one of these parks on Saturday," environmental analyst Matt Tobias said.
Tobias says the Big Sioux River one of the biggest parts of South Dakota's largest city.
"We care about the river and the river is a vital part of our community and especially with our bike trail system, it runs all throughout the river and Sioux Falls," Tobias said.
For those who ride the river often, they want to see it cleaned up too.
"Hopefully with everyone helping over the whole city we'll make a big impression on our river," South Dakota Canoe and Kayak Association Mary Finck said.
Finck says the group has cleaned up the river a lot, but there is more to be done.
"Just to keep things out of the river and keep things picked up and cleaned up, it just make it look better and it's just nicer to use it," Finck said.
Anyone can help clean up this weekend and the event is from 8-11 a.m. For a map of parks participating visit www.siouxfalls.org/green.