 Off-road winter service vehicles mounted on caterpillar tracks are known as snowcats.Snowcats are commonly fitted with snowplows or snow groomers, and are used by ski resorts to smooth and maintain pistes and snowmobile runs, although they can also be used as a replacement for chairlifts.Military winter service vehicles are heavily armoured to allow for their use in combat zones, especially in Arctic and mountain warfare, and often based on combat bulldozers or Humvees.