Huge Columbian mammoths once roamed the area now known as Waco, with the large elephants weighing as much as 20,000 pounds.

In 1978, the bones of two mammoths were discovered, and since then the skeletons of nearly 20 more of the huge creatures have been part of an ongoing excavation project near the confluence of the Brazos and Bosque rivers.

The archeological site – co-owned by the city of Waco and Baylor University – has been accepted into the National Park System.