the dried manure of animals has been used as fuel throughout history. dried manure (usually known as dung) of cows was, and still is, an important fuel source in countries such as india, while camel dung may be used in treeless regions such as deserts. on the oregon trail, pioneering families collected large quantities of "buffalo chips" in lieu of scarce firewood. it has been used for many purposes, in cooking fires and to combat the cold desert nights.