It was a rainy day in 2014 when Todd Surovell, an archaeologist working at a nearby dig site, wandered into the Pioneer Museum in Douglas and found a massive mandible, humerus, radius, ulna and teeth lying in a display case. They were mammoth bones.

He didn’t know it yet, but Surovell had just stumbled onto cluesto a mystery he’d spend years trying to solve.

His first leads were part of the display. A label read “Bed Tick Creek” explaining that the bones had been found nearby at a site discovered by R.T. Bird of the American Museum of Natural History and that the bones were a gift of William R. Eastman.

Surovell, a professor and head of the anthropology department at the University of Wyoming, immediately wanted to know more. He was at the time excavating fossils of a different mammoth nearby and has a particular interest in the ancient animals. Especially if there is a chance they lived alongside humans.

About 13,000 years ago, what is now Wyoming was home to giant ground sloths, short-faced bears, dire wolves, sabre-toothed cats, camels, mammoths and the first humans. A large Columbian mammoth bull could weigh 20,000 pounds, Surovell said. The massive animals roamed the Earth for 1.8 million years, only to go extinct shortly after the arrival of the first humans, Surovell said. It’s still a contested debate in the scientific community whether humans played a role in their extinction.

And the answer might lie in sites where humans and animals interacted — spots where the early people might have felled or butchered a mammoth. There are probably 15 of these sites in North America, Surovell said. Several are in Wyoming. The bones in the glass museum case could be from another one not yet documented.

For years, Surovell’s research on early humans hunting mammoths mostly relied on other people’s field work. He started excavating sites in 1992, but hadn’t worked at a dig site with signs of both humans and mammoths until 2014.

“That’s how uncommon they are,” he said. “It’s a dream-come-true to work on sites from this time period. So you just have to chase down every clue and every lead you have.”

Surovell had no idea if the bones in the case came from a mammoth from the period in question, he just knew he needed to find out more.

The museum’s director showed Surovell a letter dated June 21, 1958, from Loren Clark Bishop to Wyoming State Geologist Horace Thomas about the bones now in the museum.

Bishop described mammoth bones he’d found on his property in 1938. He’d dug out a few and protected several feet of exposed vertebrae found underneath an overhang, by collapsing the top of the bank to protect the exposed bones, he wrote. He’d written to request help excavating the bones he believed were still there.

And there, for the moment, Surovell’s trail went cold. He found nothing in his research that documented an excavation of a mammoth in the area during that period. It was frustrating, but it also gave him hope. The mammoth was probably still there.

The hunt continued.

Surovell reviewed the correspondence between Eastman, who’d gifted the bones to the museum, and Bird, who according to the museum, discovered the site. According to the letters, Bird visited Eastman in 1938 to see about helping recover more of the mammoth but reported he was unable to find more bones.

Surovell couldn’t find information on how Bishop, the property owner, and Eastman are connected, only that Eastman eventually acquired the land from Bishop where the mammoth was found.

Again, Surovell found himself at an impasse, unable to find any other information.

Until last year when Surovell radiocarbon-dated a sample from the humerus, looking for more clues. It showed the mammoth lived between 12,700 to 12,900 years ago.

“Then it got a whole lot more interesting,” he said.

If the mammoth had been 40,000 years old, Surovell might have walked away from the case. But this mammoth lived when humans were in the neighborhood. Its final resting place could be one of those rare sites that sheds light on life of the area’s earliest people.

“What is it like to be the first humans in a place and how would you make a living?” Surovell said. “How would you organize yourself socially? It’s an opportunity in our species that few ever had — to be the first humans to inhabit a place.”

And the sites where they intersect with animals help answer those questions. Surovell stayed on the case.

It’s been 60 years since the last documentation of the mammoth. Erosion could have destroyed the site. Someone else could have discovered it and removed the bones. But Surovell thinks it might still be there. He just needs to know where to look.

He’s confident he’s getting warmer in his search. A letter he found from Bishop describes a quarter section — the American West was divided and plotted into square-mile sections — on land he owned. Bishop describes a cut bank and describes the geology of the area.

“When you put all those things together it really narrows it down,” Surovell said.

Except for one problem. Bishop didn’t own the quarter section he describes in the letter. There is an area that matches his description, however, and it’s near Bed Tick Creek, about 6 miles — one range — from the township and range coordinates noted by Bishop. Did he purposefully disguise the exact location by changing one number, or did he make an error?

Surovell has narrowed his search to a 30- to 50-yard stretch of land. This summer he found a site with stone tools. He took soil samples to radiocarbon date. He’s confident he’s getting closer.

The Pioneer’s current director Mel Glover located a small brown paper bag of mammoth bone fragments in a storage room in the museum. It was labeled to have come from Bishop’s site, July 15, 1958, by Bishop, Hildebrand and Vetter, all without first names attached.

More clues.

But the mystery remains unsolved. Surovell’s hoping the public can help. Tips often lead to exciting archaeological finds, he said. People report teeth they find while digging a ditch, or bones they discover while fixing a fence.

This time Surovell is looking for any information related to the missing mammoth. He’s hoping for letters, journal entries or even family stories about a mammoth skeleton in Converse County. He’s hoping to find someone related to Bishop, or one of the other people associated with the lost site.

Surovell realizes the mammoth he’s hunting could have died naturally. Humans might not have been involved. But he wants to find out.

Send in a tip:

Are you related to L.C. Bishop, Hildebrand or Vetter? Have you heard of this site? Email Todd Surovell at [email protected] or call 307-766-5136.