I am traveling near Waco TX and stopped at the Mammoth National Park. This is an active archeological site for the Columbian Mammoth. The Columbian Mammoth is the largest mammoth, height 14 feet, basically 2 story building. The name is not related to Columbia or South America, but Christoper Columbus.
Back in 1978, 2 teenagers playing on land near Waco discovered a large bone. They brought it to the university were it was discovered to be a mammoth leg bone. They originally thought the site just contained the remains of one mammoth, but soon discovered there were many. They ended up putting a building around the excavation site and they are still slowly working the site.