On the day we visited with him, youngsters from Orthopaedic Hospital in Los Angeles have come to Bear Mountain to spend some time out of their wheelchairs and on the slopes.
John says it's a labor of love that brings him back every winter -- on his own time and on his own dime.
"I like the satisfaction that I get from just seeing the people you're out there helping, the joy they get from it," said John.
It's hard enough learning to ski without disabilities. That's why volunteers like John make such an impact. The bigger the challenge, the bigger the sense of accomplishment.
Sixteen-year-old Fanny Jaramillo is getting pretty good at it. She's been coming to Bear Mountain for three years and says there's nothing like the feeling of freedom she gets from skiing.
"It gets me to know that I can do this, even though I'm in a wheelchair," said Fanny.
"Their goal may be to just make one run," said John. "And if I can help them make that one run, that's great. If they want to progress on, then hey, I can help them do that, too."
And if you fall, get back up. The lessons John teaches last all year 'round.