Mammoth bones digging continues south of Kennewick

Researchers and volunteers continue to slowly excavate the 17,450-year-old skeleton of a Columbian mammoth just south of Kennewick.

The dig is in its fourth full year and word has spread among area schools, said Gary Kleinknecht, a retired teacher and education director for the MCBONES Research Center Foundation of the Coyote Canyon Mammoth Site.

He's been busy leading school tours, particularly for second-grade and middle-school classes, both of which have curriculum that fits in with the scientific dig.

But the general public also can visit the site. Tours are offered on a weekend once a month when the weather is good, with the next tour scheduled for June 14.

The excavation has found ribs, vertebrae and a couple of foot bones of a single animal since work began in fall 2010. A tail bone and shoulder bone had been found earlier before the land was purchased and donated for research and education.

Last year work focused on locating the pelvis.

"We did not find it," Kleinknecht said. "That doesn't mean it is not there. ... A lot of geological forces move things around over 17,000 years."

The bones found so far indicate the skeleton was buried largely intact. However, the right ribs were jumbled and had bite marks on them, suggesting that an animal had fed on the carcass before it was buried.

This summer work is continuing to excavate bones already located, and a research project is being considered to date the unrelated bones, seeds and other organic matter found in the soil layers at the dig site.

The mammoth's age is known through radiocarbon dating, but "we would like to know how the layers above the bone bed came to be," Kleinknecht said. That would add context to information about the mammoth.

At 17,450 years old, the skeleton is fairly recent for a North American mammoth. Columbian mammoths roamed the area from about 400,000 to 11,000 years ago, dying out with most other large mammals at the end of the last major Ice Age.

The mammoth would have died during the time of the Missoula floods, when 40 to 100 floods swept across Eastern Washington between 15,000 and 20,000 years ago and a temporary lake built up over the Tri-City area as water backed up behind the Wallula Gap.

The mammoth was an adult, but judging by the lack of arthritis in its bones, it did not live to old age. It would have stood 10 to 13 feet tall at the shoulder.

It's uncertain whether the mammoth was a Tri-City-area resident -- several possibilities of how the skeleton came to be near Kennewick have been suggested.

Most animals lived in low lands near water, and the mammoth could have been washed away by the flood water anywhere from North Idaho to the Tri-Cities. The carcass could have settled on the shoreline of the lake and then been covered with sediment during the next flood.

Or the mammoth could have been an early resident of the Tri-City area that came down to get a drink from the temporary lake and become mired in the mud.

There's also the possibility that it floated into the region encased in an ice sheet. Underneath the bones are angular granite rocks believed to have floated into the region encased in ice that then melted here during the Ice Age floods.

Teachers interested in a class trip to the Coyote Canyon Mammoth Site may email Kleinknecht at res20jii@frontier.com.

Public interested in signing up for a tour should call Donna Van Beek at 509-989-1449.

There is no cost for tours, but donations are accepted to help develop the Coyote Canyon Mammoth Site into an outdoor classroom and laboratory for students, teachers and community volunteers.

-- Annette Cary: 582-1533; acary@tricityherald.com; Twitter: @HanfordNews