Wooly mammoths lived in Siberia and North America from about 5 million to as recently as 4,000 years ago.

They stood the same height as African elephants, up to 11 feet at the shoulder, but with long shaggy coats and much longer tusks.

Within one of those tusks, scientists found a remarkable story.

Mammoth tusks were just specially developed teeth, which grew new layers every year, from the inside.

Recently, scientists measured strontium in each layer of a tusk from one mammoth found in Alaska. All land animals ingest tiny amounts of strontium in food and water over their lifetime.

The researchers then matched the strontium signatures in each tusk layer to the strontium found in rodent teeth in different parts of Alaska. They could use this technique to map the lifetime travels of that one mammoth.

He was born 17,000 years ago in the Lower Yukon River Basin and lived there for the first year of his life.

From age 2, he roamed between two mountain ranges, likely with his herd, until he reached maturity at 16.

As a solitary adult bull, he covered an even larger area, traveling hundreds of miles, probably to stay in good grazing.

At age 28, he kept to a much smaller circuit, perhaps because of disease or injury, until he died, seemingly of starvation.

Little did he know, the tusks he left behind would tell his story.