Volunteers at the Coyote Canyon Mammoth Site have unearthed another clue about the animal that came to rest on a hillside near Kennewick about 17,500 years ago.
It appears the Columbia mammoth may have been a male.
The guess is based on the growth plate of the upper front leg found buried in the ground.
It had not fused, and researchers believe that like elephants, female mammoths mature earlier and a female would have had a fused foreleg.
But they won’t say for certain the skeleton is the remains of a male until they unearth a pelvis they hope to find still buried in the ground.
Excavation of the bones began in 2010 and has been a slow, painstaking process.
The dig is unlike other mammoth excavations in the Northwest.
It’s been undertaken as a community volunteer effort and as part of a citizen science project that goes beyond just pulling out the bones. Volunteers are conducting a paleoecological study, carefully sifting through each trowel of dirt taken from the excavation site to the exacting standards of modern paleontology.
In time, they hope to learn the history of the climate of the Mid-Columbia over up to 20,000 years, including during the time the Ice Age floods likely deposited the mammoth’s body near the Tri-Cities.
“We think there is some pretty important science we are doing, science that hasn’t been done to this degree in our part of the country, even by professionals with funding,” said Gary Kleinknecht, a retired Kamiakin High teacher and the volunteer who serves as the site’s education director. Money for the project comes from community donations and a few small grants.
The skeleton was discovered during excavation on private property in the Horse Heaven Hills in 1999. Excavation halted, and when the land went up for sale a local farming family purchased it to turn it into a nonprofit research center for teachers, students and community volunteers.
Since serious digging began almost eight years ago, volunteers have excavated three large bones — a scapula or shoulder blade and two upper front leg bones. The animal was large, likely standing 10 to 13 feet tall at the shoulder, making it bigger than modern day elephants.
Volunteers also have found two tail bones, two foot bones and numerous ribs and vertabrae.
Kleinknecht estimates about 20 percent of the ribs and vertebrae have been found. More can be seen partially exposed at the dig site but not yet excavated.
Some bones, including the lower jaw bone, ended up in private hands before the MCBONES Research Center Foundation took control of the site.
A study of the jaw has helped date the mammoth, putting its age at about 40 at the time of its death.
Mammoths have six sets of four teeth in their lifetimes, and this animal was on its sixth set, with some of the teeth not completely exposed yet.
If it were a female, its upper front leg bone likely would have been completely fused by age 40 to allow calcium to go to its young, Kleinknecht said.
He thinks the mammal had the misfortune of grazing in front of one of the Ice Age floods that flowed south across Washington state. The flood waters covered what’s now the Tri-Cities as water backed up behind the narrow opening through Wallula Gap.
The dig site is at an elevation of about 1,060 feet, and floods may have been deep enough to reach the area about seven times. In comparison, the McNary pool of the Columbia River now sits at an elevation of about 340 feet.
Radiocarbon dating put the flood that deposited the Coyote Canyon bones at about 17,450 years ago.
Researchers suspect the carcass of the animal was swept along with flood waters and deposited on the hillside near Kennewick as waters receded.
“One of the things we’ve been looking at is who’s been gnawing on the ribs,” said volunteer Jan Griffin, of Richland.
It appears, based on their size, that the marks were made by two squirrels and a type of rabbit before the bones were completely buried by the next flood.
Much of the current excavation is focused on taking down another vertical slice of the hillside, in the expectation that more of the skeleton is buried farther back in the hillside.
The bones found so far have been found in the general shape of a skeleton, but likely have shifted with movement of the hillside over the years.
The ribs excavated so far looked like a game of pick-up-sticks, said volunteer James Hallock of Benton City.
As dirt is removed, it is sifted to find clues of what used to live in the Mid-Columbia.
Volunteers have found the remnants of snakes, lizards, ground squirrels, mollusks and even a 10-inch piece of bone from a camel’s leg. Camels roamed the Mid-Columbia at about the same time as mammoths, Kleinknecht said.
Because different animals required different wet or dry climate conditions, the finds are expected to eventually tell a story of the Mid-Columbia climate through the centuries.
Now excavation is done four days a month on two weekends from spring through fall.
More volunteers are needed who can commit to that schedule, Kleinknecht said. Those interested may call him at 509-627-1654.
No special skills are needed. Volunteers are trained first to support those excavating and screening the dirt and should have the patience to work carefully to exacting scientific standards.
“We do a lot of stuff Indiana Jones never did,” Griffin said. “It’s really meticulous, dirty work.”
Volunteers also have brought specific talents to the project, like that of Neil Mara, of West Richland.
He’s using his computer expertise to make three-dimensional images of the bones.
Kadlec Regional Medical Center in Richland is allowing bones to be imaged by CAT scan during off hours, providing data to create replicas with a three-dimensional printer.
Kleinknecht’s goal is to make a half-scale replica of the mammoth that can be used in educational programs for schoolchildren.
Field trips are already being booked this fall by elementary school classes to visit the excavation site. Volunteers expect more than 1,000 students to visit this year.
The public also will have a chance to tour the dig site this fall.