Ski-doo (n.)

in early use often skee, "one of a pair of long, slender boards or slats fastened to the feet and used to glide over snow," 1883 (there is an isolated instance from 1755), from Norwegian ski, related to Old Norse skið "long snowshoe," literally "stick of wood, firewood," cognate with Old English scid "stick of wood," obsolete English shide "piece of wood split off from timber;" Old High German skit, German Scheit "log," from Proto-Germanic *skid- "to divide, split," from PIE root *skei- "to cut, split."

THE new sport which has lately been introduced at Beloit is skeeing. They are long ash planks, carefully planed and turned up at the end, and are warranted to take you down hill quicker than a wink. After some practice performers become very expert, and the speed with which they go is something surprising. [Beloit College, Wisconsin, Round Table, Dec. 18, 1885]

Ski-jumper is attested from 1894; ski bum, a skiing enthusiast who works casual jobs at resorts for the opportunity to ski, is attested by 1960; ski-mask, originally to protect the face while skiing, is from 1963; noted as part of criminal disguises by 1968.