Grasslands, or prairies, occur in areas that are too dry to support trees, but too wet to be deserts. Badlands National Park contains mixed-grass prairie, meaning that it contains tall-grass, such as big bluestem and prairie cordgrass, and short-grass species such as blue grama and buffalograss as well ashundreds of species of wildflowers and forbs. The landscape, which was once forest, now contains a multitude of plants and animals uniquely adapted to what appears to be unforgiving and harsh conditions. Grasses, able to withstand high winds, long spells of dry weather and frequent fires, thrived. Grazing animals became abundant and grasses, better suited to withstand constant trampling and grazing, spread and overtook ancient forests. Today, many animals--black-tailed prairies dogs, mule deer, pronghorn (commonly call antelope), bison, coyotes, and bighorn sheep--adapt to, and even thrive under the conditions in Badlands National Park.