Marmots are members of the genus Marmota, in the rodent family Sciuridae (squirrels).
Marmots are generally large ground squirrels. Those most often referred to as marmots tend to live in mountainous areas such as the Sierra Nevada in the United States or the European Alps. However the groundhog is also properly called a marmot, while the similarly-sized but more social prairie dog is not classified in the genus Marmota but in the related genus Cynomys.