Snocross (also snowcross) is a racing sport involving racing specialized high performance snowmobiles on natural or artificially-made tracks consisting of tight turns, banked corners, steep jumps and obstacles. Riders race at speed of up to 60 miles per hour (96 kilometers per hour). Jumps are up to 30 feet (9 meters) tall, so riders travel up to 130 feet (40 meters) before they touch the ground. According to the World Snowmobile Association which governs snocross, watercross, and hillcross racing, snocross is the most popular form of snowmobile racing. Snocross was derived from the sport of motocross. The name is a portmanteau of the words "snowmobile" and "motocross". The sport uses a snowmobile instead of a motorcycle, and a snow/ice surface instead of dirt. The snow/ice surface which is either natural or man-made. Tracks are generally located in higher latitudes in the Northern Hemisphere since temperatures below freezing are required to maintain the frozen track surface. Motorcycle riders in motocross and supercross frequently compete in snocross in the winter. Snocross became an event at the X Games in 1998. X Games is a popular gathering place for some snow-related sports in the United States. The course at the first snocross event at the X Games resembled a motocross course; it was significantly longer than courses are now. It had deeper holes and higher jumps that are now filled in with snow.