Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses , herbs, and shrubs , rather than trees , as the dominant vegetation type. Temperate grassland regions include the Pampas of Argentina , southern Brazil and Uruguay , as well as the steppes of Eurasia. Lands typically referred to as "prairie" tend to be in North America . The term encompasses the area referred to as the Interior Lowlands of Canada , the United States , and Mexico , which includes all of the Great Plains as well as the wetter, hillier land to the east .
In the U.S., the area is constituted by most or all of the states of North Dakota, South Dakota , Nebraska, Kansas, and Oklahoma, and sizable parts of the states of Montana , Wyoming, Colorado , New Mexico , Texas, Missouri, Iowa , Illinois, Indiana, Wisconsin , and western and southern Minnesota . The Central Valley of California is also a prairie. The Canadian Prairies occupy vast areas of Manitoba, Saskatchewan, and Alberta.