The Pawnee Buttes are two prominent buttes in northeastern Colorado. The west butte is located within the Pawnee National Grassland, while the east butte is on private land in Weld County. Rising approximately 300 feet (91 m) above the surrounding plains, the buttes are erosional remnants left standing in isolation as the surrounding High Plains surface has gradually worn away. The lower portions of the buttes are composed of relatively soft, clay-rich sedimentary rock called the Brule formation. The Brule formation is protected by an overlying layer of sandstone and conglomerate sediments called the Arikaree formation, which are more resistant to weathering.

In geomorphology, a butte is an isolated hill with steep, often vertical sides and a small, relatively flat top; buttes are smaller landforms than mesas, plateaus, and tablelands. The word butte comes from the French word butte, meaning knoll ; its use is prevalent in the Western United States, including the southwest where mesa is used for the larger landform. Due to their distinctive shapes, buttes are frequently landmarks in plains and mountainous areas. To differentiate the two landforms, geographers use the rule of thumb that a mesa has a top that is wider than its height, while a butte has a top that is narrower than its height.