The Columbian mammoth (Mammuthus columbi) was a descendent of Mammuthus meridionalis, and is an extinct species of elephant of the Quaternary period that appeared in North America (in the present United States and to as far south as Nicaragua and Honduras) during the late Pleistocene. It is believed by some authorities to be the same species as its slightly larger cousin, M. imperator, because of their similarities in fossil location and size.
The Columbian mammoth was one of the last members of the American megafauna to go extinct, with the date of disappearance generally set at approximately 12,500 years ago. However, several specimens have been dated to 9,000 years ago or less, and one near Nashville, Tennessee, was reliably dated to only about 7,800 years ago. According to some research there is evidence of the interbreeding between the Columbian Mammoth and the woolly mammoth.The Columbian mammoth was a savanna and grassland inhabitant, similar to the modern African elephant and it probably had little hair. Large males ranged from 3.7–4.0 m (12–13 ft) and weighed between 7–9 metric tons (7.7–9.9 short tons) with spiralled tusks that could grow up to 4.25 metres (13.9 ft) long.
The remains of Columbian mammoths were discovered in the La Brea Tar Pits, located in Los Angeles, California, and the skeleton of one of them is on exhibit in that site's museum. The Waco Mammoth Site in Waco, Texas, has produced so far a collection of bones of 19 females and juveniles who are believed to have died in the same flood event, as well as the skeletons of other mammoths who died in separate flood events. This mammoth also lived in Mexico, where its remains are very common. A large individual is the central exhibit in the Regional Museum of Guadalajara, in the Mexican state of Jalisco.
In 1998, the Washington State Legislature approved the Columbian mammoth as the state fossil. Additionally, a specimen found in Nebraska in 1922 and named "Archie" is the state's official fossil. "Archie" is currently on display at Elephant Hall in Lincoln, Nebraska, and is the largest mounted mammoth specimen in the United States