Considering how many extreme sports Red Bull has its fingers in, it probably comes as no surprise that the company runs an annual event where big trucks slide around on frozen tundra. The machines, called Pro 4 trucks, are big, all-wheel-drive race pickups equipped with studded snow tires, making for some of the most hair-raising side-by-side racing action you can find. The event — "Frozen Rush," Red Bull calls it — takes place at Maine's Sunday River Ski Resort on January 8th after qualifying the day before, and it's almost certainly going to be completely nuts.