Wingsuit base jumping is a new incarnation of a winter sport you probably have heard of before--base jumping. With wingsuit base jumping, you literally gain the ability to fly with the addition of a wingsuit with "wings" to the usual assortment of protective gear that base jumping requires. With this incredible extreme winter sport, you ski off a cliff with your skis on, then kick away your skis and use your wingsuit alone to fly the wind currents and land yourself safely.
With kite snowboarding, you will be using a little extra help from an attached parachute (called a "kite") that will pick up the wind currents and help to propel you along on your snowboard at faster speeds than you could achieve without the kite. This extreme winter sport requires better than average lower body strength and fine-tuned coordination, as well as knowledge of how to control your snowboard if your kite suddenly gets more of a lift than you were expecting.
Heliskiing and Heli-snowboarding
Heliskiing allows skiers of all skill levels to travel past the slopes you can reach on foot with a little help from their friendly neighborhood helicopter pilot. Snowboarders can also do the same. With heliskiing and heli-snowboarding, the goal is to drop the skier or snowboarder off at the top of a remote and inaccessible peak, from which you can make your way down as quickly or slowly as you like to the ground level.
With snow kayaking, you simply use a kayak to do what you would normally expect your skis or snowboard (or even a nice winter sled or toboggan) to do for you. The challenge comes in part with hauling your kayak up the side of the slope, and in part with controlling the kayak on the way down to the ground level again. While many snow enthusiasts do this on lower or moderate slopes, the most extreme form of snow kayaking can take you right up to the mountain peak itself.
Polar Bear Plunge
The polar bear plunge is in part one of the craziest winter sports you've never heard of, and in part a sentimental and commemorative gesture that is guaranteed to be remembered by the jumper and their nearest and dearest. To perform the polar bear plunge, dress in as little as possible (or nothing at all). Find a very cold, appropriate depth body of water. Then jump in, and jump right back out again. Be sure to get a friend to take your picture too!