Shaun White Surprises Triple Amputee Snowboarder Zach Sherman for Fun-Filled Day on the Mountain

“It felt like such an honor to be on the same hill and the same run riding with one of the greatest snowboarders of all time. It was very surreal,” Sherman tells PEOPLE

Shaun White's got some fierce competition on the slopes!

The three-time Olympic gold medalist surprised Zach Sherman, a triple amputee snowboarder from Harrisburg, Penn., for a few runs at Woodward Park City Resort in Utah recently – an experience Sherman, 37, calls "surreal."

"After a few warm-up laps I had a suspicion something else was going to happen that day," the athlete, who started snowboarding in the late '90s, tells PEOPLE. "Then, all the sudden, Shaun casually walked up to me and asked if I wanted to do a few laps. I was just stunned!"

Sean Ryan/Challenged Athletes Foundation

"Riding up the lift, all I could think was, 'Please don't fall in front of Shaun White!' " Sherman continues. "After everyone was strapped in at the top, my nerves kind of subsided and I couldn't wait to start riding next to Shaun. As we were going down the hill, I kept trying to watch him ride. It felt like such an honor to be on the same hill and the same run riding with one of the greatest snowboarders of all time."

Sherman – who has watched White, 35, snowboard since he was in high school – says he couldn't believe he was riding side by side with one of the best winter athletes in the world.

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"Not only was I riding next to him, but he was there to ride with me because of the Challenged Athletes Foundation," he says. "It's a memory I won't soon forget. I am grateful for the opportunity."

At the end of their runs, White presented Sherman with his 2022 CAF grant – a moment Sherman will always be thankful for.

Sean Ryan/Challenged Athletes Foundation

The Challenged Athletes Foundation (CAF) provides access and opportunity to adaptive athletes of all ages and abilities, Christy Fritts, who manages media and athlete relations for the organization, tells PEOPLE.

"CAF is committed and focused on positively impacting athletes with life-changing grants around the world by providing adaptive sports equipment not covered by medical insurance," explains Fritts. "We empower lives through the power of sport and believe that everyone should have access to sports and be able to pursue their athletic dreams."

Sherman first applied for a CAF grant in the fall of 2015 after meeting his best friend, Travis Ricks, while volunteering at a camp for kids with limb differences the same year.

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In July 2010, Sherman was involved in a motorcycle accident that resulted in him losing his legs and his right arm.

"I spent more than six months in the hospital and an additional two months in a physical rehab learning how to do everything from brushing my teeth and writing with my left hand to walking with prosthetic legs," he tells PEOPLE, adding that "having the right support group of friends and mentors was a big help" in his recovery.

"After my accident, it took me years to figure out how to safely get back on a snowboard," he continues. "In 2017, I finally got back on a board at an event specifically for disabled snow sports, The Hartford Ski Spectacular."

Sean Ryan/Challenged Athletes Foundation

And while snowboarding started out as a "fun hobby" for Sherman early on in life, being able to get back on the mountain has "become so much more" to the CAF athlete.

"Everything has gotten much more difficult for me as a disabled athlete. Running is ten times harder and more strenuous," explains Sherman. "Hand cycling with one hand has caused premature wear on my only arm, but snowboarding, despite the physical demand, has been most rewarding."

Adds Sherman: "I love seeing the looks on other people's faces when I ride past them down the mountain only to be greeted with, 'Dude that's awesome!' at the bottom of the chairlift."

Snowboarding isn't the only sport Sherman's looking to dominate, though.

"I'd like to find a good summer sport that fits well for cross-training so I'm in better shape at the beginning of the snowboard season," he says. "I've been thinking about wakeboarding but haven't had a chance to try it…yet! I'm sure CAF will find a way to get me on a board."

"They do that…" he continues. "They don't focus on what people can't do, they focus on what everyone can do, and help make that happen."