At Aurora's Arapahoe Park Racetrack, the smell of sunscreen and roasted turkey legs is heavy in the air. It's the last day of summer, and the crowd is ready for some serious pumpkin tossing — especially after last year.
"I think we're all scarred from last year," said Brittni Ehrhart, spokesperson for the annual Punkin' Chunkin' Colorado event. She's especially happy about the weather.
Rain, snow and winds reaching up to 90 miles per hour put a halt to some of the 2018 competition. It's the reason the event was moved up several weeks this year.
A quick synopsis for those new to punkin' chunkin': teams from all over the country build machines to see who can throw a pumpkin the farthest. Categories include air cannon, catapults, trebuchet, centrifugal and torsion.
Daniel Bertrand, 23, is a newcomer to the contest with his machine.
"I'm calling it 'The Sentinel,'" Bertrand said proudly, standing in front of the wooden trebuchet. "It's big and tall and it stands guard."
Bertrand got into the sport a little differently than most of the engineer-types here.
"I'm actually a history major; I'm not an engineer," he said. "And I've looked at a bunch of different medieval sources to build this so I think this is the most authentic medieval trebuchet that's ever been here at Punkin' Chunkin'."
As part of his senior thesis at Utah State, Bertrand based much of The Sentinel's design from "The Elegant Book of Trebuchet." The manuscript was written in the 15th century.
"These things were the frontline artillery for about 300 years," he said.
When he practices with bowling balls, it can throw more than 900 feet. With pumpkins, about 600.
But when you're talkin' punkin' chunkin', 600 feet is just the beginning.
Greg Wolfe's centrifugal machine "Inertia III" is about as high-tech as they come. It uses a Boeing jet turbine engine from the 1950s purchased on eBay.
Wolfe, who runs a small manufacturing company in Arvada, has been competing since 2006. He started with a small trebuchet before moving up to the bigger machines.
But the 2011 Punkin' Chunkin' World Champion says it's not all about power. There's an art to it, too.
"It's truly amazing what kind of force it takes to throw a 10-pound object 1,000, 2,000 feet," Wolfe said. "And the beauty of this sport is you don't just throw a rock or something, it's a pumpkin, a gourd. So you have to put about 500 Gs on it, but do it delicately to where it leaves the machine intact. That's the real fine line there, is you want to put enough forces on it to get it out there, but not to where you 'pie' the pumpkin."
When a pumpkin breaks apart before it hits the ground, it's called a "pie." To avoid that requires expertise in engineering, physics and even horticulture. Your average, run-of-the-mill pumpkin isn't good enough for chunking. It has to be a dense gourd — la estrellas or jarrahdales — are best, according to Wolfe.
But while he loves the competition, for him one of the best parts is seeing young people taking it up.
"It really inspires the kids to learn engineering, to learn mathematics, learn history, there's so much involved in this sport," Wolfe said.
Boulder 12-year-old Sophia Nuttycombe got the idea to try out the sport after watching her dad compete a few years ago. She remembers him telling her and her brother that the machine was off limits.
"He said, 'If you want to climb on a machine, you better build your own,'" Nuttycombe said.
This year, she created an all-girls team — The Chunkers of Artemis — to compete in the catapult division. The name came from the Greek myth of Artemis, the protector of young girls and goddess of the hunt.
Their catapult, "Squirrel Hurler," has a 12-foot arm and is powered using bike innertubes. Their best round of the competition hurled the pumpkin 418 feet, enough for them to nab first place in their punkin' chunkin' debut.
Greg Wolfe also ended up with a first place trophy in his category with a distance of 1,192 feet, although his last round of the day never even left the launch pad.
"Basically the way I loaded the pumpkin, I didn't have it tight enough," he explained. "The wind resistance kicked it out before I ever hit the trigger so — that was pie, that was no good … That's the way this goes."