SILVERTHORNE, Colo. (AP) — Simon Beck carefully plots his course before shuffling through a windswept snowfield high in the Rocky Mountains.

Using a compass, snowshoes and his background as a cartographer and competitive orienteer, the 61-year-old British artist and a handful of volunteers recently tromped across a frozen reservoir near the ski resort town of Silverthorne, west of Denver, to create a massive, geometrical design on a fresh canvas of snow.

The result after more than a dozen hours of labor in freezing weather and under an unrelenting sun was a spectacular spiral pattern the length of about two soccer fields.

“I hope it makes people more aware of the snow and the environment and the beauty of it and how we need snow,” Beck said after completing the drawing. “And I think it’s a really beautiful and unique art form.”

Beck finished his day with high fives from his volunteers and congratulations from people who gathered on a nearby hillside to watch his progress.

But it hasn’t always gone this smoothly. It’s never clear how many workers will show up. And if bad weather rolls in, an intricate piece of art can quickly disappear.

“It’s very frustrating when you plod around for hours and hours and hours and then the wind blows it away before you’ve finished it,” he said.

Beck started making fractal drawings in snow in 2004 outside his winter home at France’s Les Arcs ski resort when he trampled out a five-pointed star spanning more than 300 feet (91 meters) “just for a bit of fun.” He didn’t realize how good it looked until he rode a ski lift the next day and saw it from above.

“Snow drawing, which to me seems like a fairly obvious idea, was not something anyone else had ever done as far as I could tell, and I was really surprised by that,” he said.

Beck has completed about 330 snow drawings and 120 in sand, and has set a goal of 1,000 total drawings by the time he’s 80. His drawings are commissioned around the world, he has published a book, and he has attracted a dedicated fan base.

Carolyn Tiller, who has been following Beck’s career for three or four years, watched his progress on the reservoir and delivered him and his crew cookies and spiked cocoa.

The 62-year-old retired gemologist said Beck’s art reminds her of her childhood playing with a Spirograph, the classic toy that makes it easy to create detailed geometric drawings.

“I also really appreciate someone who can make something by one step after another step after another step,” said Tiller, who lives across the street from the reservoir. “They say the greatest journeys start with one step, and that’s a perfect example.”