(began 2 million years ago)
The Quaternary Period (in which we live today) is characterized by dramatic changes. The Pleistocene Epoch, a time when glaciers covered much of North America, started with widespread migrations of mammals, and ended with massive extinctions. The oldest record of human occupation in North America is around 12,000 years ago. In the time that human beings have inhabited North America, we have had a profound effect on its animals and plants.
Will we preserve the diversity of life so richly celebrated in the Cenozoic?
Endangered species today include the loon, timber wolf, and Kemp's ridley sea turtle. The National Park Service is among the many public and private agencies entrusted with helping to protect these animals and to preserve the diversity of life throughout North America.