An estimated 1,000 people donned costumes and took to a Colorado creek for the 11th annual Tube to Work Day.

The annual event in Boulder drew about 1,000 participants Wednesday morning, with many clad in colorful costumes or office wear as they donned their bicycle helmets and rode tubes through Boulder Creek.

The participants started at Eben G. Fine Park and floated down the river.

Tube to Work Day started in 2008 with friends Andy Gruel and Jeff Kagan, who came up with the idea of using inner tubes to go to work via the creek. The pair said the event has been growing exponentially each year.

"I think it kind of embodies what people love about Boulder, being outdoors, enjoying our natural resources, alternative commute and a lot of wacky people here who don't mind getting into costumes and into the water at 8 a.m.," Kagan told KCNC-TV.

Kagan said he would like to see the event spread to other cities with rivers and creeks.

"I want to tube to work in Denver, I want to tube in Fort Collins," Kagan told the Boulder Daily Camera. "I want politicians to tube the Potomac to the Capitol."