
The Great Plains is a large and very important grassland ecosystem covering roughly one-fourth of the United States. Human activity has had an impact on this environment for thousands of years, especially since the 1800s, when hunters killed off almost all of the enormous herds...

The Great Plains is a large and very important grassland ecosystem covering roughly one-fourth of the United States. Human activity has had an impact on this environment for thousands of years, especially since the 1800s, when hunters killed off almost all of the enormous herds...