"I ducked down, protected my head and waited for the worst," he said.
Moments later, Cleveland said, the twister lifted the cart and threw it on top of a caddy walking nearby. The caddy, a man in his 50s, was taken to a hospital with minor injuries, said Capt. Diane Lord with the Aurora Fire Department. Damage was also reported to a construction trailer.
Two twisters in Park County caused damage. A funnel cloud touched down near Fairplay about 65 miles southwest of Denver at about 11 a.m., damaging the roof of a home, Park County spokeswoman Linda Balough said.
"This is amazingly unusual at 10,000 feet, very unusual for it to happen up here," she said.
Another tornado was reported a short time later, about 40 miles away near Lake George, and caused "substantial" damage at an RV park, Balough said. No one was reported injured in either tornado.
A twister also touched down in a sparsely populated area of southeast Wyoming, but there were no immediate reports of injuries or major damage.
Weather Service meteorologist Kyle Fredin said a trough of low pressure created a "large extensive line" of severe weather along the Front Range from southern Colorado to the Wyoming border.
The same system dropped snow in parts of Colorado's mountains. The Denver Post reported that about 200 riders participating in the first day of the Ride the Rockies bicycle tour got rides down from Berthoud Pass because of blizzard-like conditions.
The weather is expected to be quieter in Colorado Monday but thunderstorms could produce large hail, isolated tornadoes and heavy rain, which could lead to flash flooding in southern Nebraska, Kansas, northeast Oklahoma, Arkansas, Missouri, southern Illinois, western Kentucky and northwest Tennessee.
Associated Press writer Thomas Peipert in Denver contributed to this report.