Maybe the most prominent underaged snowboarder is Red Gerard (no need to click the link, as we pasted pretty much everything we had on him below). This kid from Frisco/Colorado is only 12 years old. And now get this: When he filmed those videos below, he was even younger!
This one also features Wes Muresan, who clocks in at a meager 6 years of age, but he is equally (maybe even more?) amazing: