That crushed rock made a lot of drainage which made the soil drier. After that the glaciers melted, then the prairie started to grow and then animals adapted to the prairie. Then a couple thousand years later settlers came and harvested it and destroyed a lot of the prairie. There are many animals on the prairie. There are prairie animals from A-Z on the prairie.
Prairie animals can go without water for a while because of the small amount of water.
There is a large variety of grass on the prairie. There is blue grass which grows up to around 6 feet. The grass is very important to the wildlife, like the meadow larks that make their nest in the grass. Prairies don't usually develop on very hilly land. Therefore they range from the Rocky Mountains to the Appalachian Mountains.