Snow grooming is the process of manipulating snow for recreational uses with a tractor, snowmobile, piste caterpillar, truck or snowcat towing specialized equipment. The process is used to maintain ski hills, cross country ski trails and snowmobile trails by grooming (moving, flattening, rototilling, or compacting) the snow on them. A snow groomer is usually employed to pack snow and improve skiing and snowboarding and snowmobile trail conditions. The resulting pattern on the snow is known as corduroy, and is widely regarded as a good surface on which to ski or ride. Snow groomers can also move accumulated snow made by snow machines as part of a process, called "snow farming".
Modern groomers built for ski slopes employ front mounted, hydraulically operated blades, powered rotary tillers and specialized shaping equipment for not only maintaining ski slopes, but also for building half pipes, ski/snowboard terrain parks and snow tube parks. Cross country ski trails are also groomed in similar fashion, but use specialized drags that imprint ski guides instead of grooming a wide path suitable for high speed snowmobile use.
A snow groomer is a tracked vehicle equipped in front with a shovel (or dozer blade) and behind with a cutter (or roller). It is usually driven by diesel engines. When the machine drives over a snowfield, it pushes snow ahead of it and, at the same time, smooths out any surface unevenness.
Manufacturers include Formatic, , Prinoth, Ratrak, Logan Machine Company, Tucker Sno-Cat, Snow Trac, Thiokol, the Ohara Corporation (Japan) and Aztec, SAS (France).