A butte is a conspicuous isolated hill with steep, often vertical sides and a small, relatively flat top; buttes are smaller than mesas, plateaus, and table landforms. In some regions, such as the north central and northwestern United States, the word is used for any hill. The word butte comes from a French word meaning 'small hill'; its use is prevalent in the western United States, including the southwest, where 'mesa' is also used. Because of their distinctive shapes, buttes are frequently landmarks in plains and mountainous areas. In differentiating mesas and buttes, geographers use the rule that a mesa has a top wider than its height, while a butte's top is narrower. Three classic buttes are Scotts Bluff (actually a collection of five bluffs) in Nebraska, Crested Butte in Colorado, and Elephant Butte in New Mexico. Among the well-known non-flat-topped buttes in the United States are Bear Butte, South Dakota, and Black Butte, Oregon.