The southern reaches of the US were perhaps home to a vast herd of migrating Columbian mammoths some 70,000 years ago.

Researchers have now carried out an in-depth analysis of a Columbian mammoth tooth unearthed at the paleontological site of Waco Mammoth National Monument in Texas. By looking at the isotopes that make up the teeth, they were able to tell where and what the mammoth ate. The analysis leads them to believe this hulking animal migrated at least 200 kilometers (124 miles) away from grasslands near present-day Austin, Texas – one of the longest migrations by a Columbian mammoth ever known.

The research was presented last week at the 2017 Society of Vertebrate Paleontology meeting, as reported by Live Science. So far, the researchers have only studied one tooth and their study is yet to be peer-reviewed. However, with further research to come, the paleontologists hope to add some vital insights into the behavior of the Columbian mammoth.

The Columbian mammoth was one of the largest species of mammoth, measuring up to 4 meters (13 feet) tall and weighing some 10 tonnes (22,000 pounds). Their huge, curling tusks were also the largest of any known species. They roamed throughout North America and Central America until they went extinct around 12,500 years ago.

The Waco Mammoth National Monument is home to the remains of at least 19 Columbian mammoths from a nursery herd who died around 67,000 years ago, most likely in a freak natural disaster such as a flash flood or mudslide. Further digs have found the remains of an unlucky camel too. The site was only discovered in 1978, but has since become a hub of paleoecological research and even become a National Monument in 2015. 

Carbon, oxygen, and strontium ratios in the mammoth tooth give an indication of the type of nutrition they ate to develop their teeth. In this instance, they found notable levels of Carbon 4, suggesting the beasts ate grasses growing in granite-rich soil, most like the soil found in Austin.

That would mean the mammoths traveled at least 200 kilometers (124 miles) from Austin to Waco, at least at one point in their life. Don Esker, a doctoral candidate in the Department of Geosciences at Baylor University in Waco, told Live Science that this is perhaps one of the largest distances researchers have documented Columbian mammoths to travel.