Quick-release skis couple to the front wheels of an ATV or other wheeled vehicle, to permit the ATV to travel over snow. The rear ATV wheels may be left unaltered, or more commonly, tracks may be substituted for the rear wheels. The ski coupling includes a drive-on runner and coupling having in one embodiment width-adjustable side walls, an over-center clamp, and a lock for securing the over-center clamp. In a second embodiment, a pivotal tire cage allows the ATV tire to be driven onto the ski, but simply by forward travel of the tire the cage pivots to constrain the tire thereon. A strap then binds the tire and cage to ensure the tire stays in place on the ski. In a third embodiment, an ATV track is converted to a runner by the application and tensioning of a ski. Additional embodiments are illustrated.