The recreational use of snowmobiles has increased at a phenomenal rate. The large number of injuries resulting from their operation prompted this preliminary study to determine the mechanism and types of injuries incurred. Often the type of injury can be correlated with the mechanics of snowmobile construction and operation. For example, compression fractures of vetebrae appear to result from inability of the spine to absorb the shock of traveling over irregular terrain. Most fractures, bruises, and lacerations result from faulty operation of the vehicles.