The Discovery of a Lifetime — Unearthing a Prehistoric Sloth at SEA

Gordon Simmons had always been fascinated by the world around him and filled his life with curiosities and keepsakes that created connection and inspiration. He was proud of his collections of records, coins, and stamps, and treasures he uncovered on the Washington coastline where he lived — odds and ends from shipwrecks that had washed up on shore. As a kid, his most prized find was 100 glass balls that had washed up on the beach one night near his home in Ilwaco. 

But his biggest discovery would happen more than 14 feet underground and 200 miles away in an unexpected place. In 1961 while working on a construction project at Seattle-Tacoma International Airport (SEA), Simmons uncovered the remains of an extinct prehistoric ground sloth that roamed the earth between 12,000 and 13,000 years ago. Six decades later it remains the only discovery of its kind in Washington state.

Not a dinosaur

Simmons started his construction career on the Long Beach Peninsula as a pile driver, and later came to Seattle in the 1950s to work on the construction boom of roads, bridges, freeways, and other critical infrastructure. 

On February 14, 1961, while working on a project to lengthen the runway at SEA Airport, Simmons and his team were digging a 14-foot hole to anchor a lighting tower when an obstruction stopped their work. Simmons climbed down into the hole to see what the hang up was. 

“He started digging with a shovel, and came up against this bone,” Simmons’ daughter Dianna Johnson said. “He realized he had found something unique, and thought to himself, ‘I think I found a dinosaur’. He yelled up to the top and said, ‘We've got a dinosaur down here. Call the university.’ That was the first thing on his mind.”

Simmons and his team paused construction for three days as the Burke Museum of Natural History and Culture at the University of Washington sent a crew of paleontologists and archeologists to excavate the bones. The rest of Simmons’ crew wasn’t happy about the work stoppage as it meant not getting paid during that time, but Simmons was fascinated. He made a point of going to the site and watching the excavation efforts. Burke Museum staff uncovered more than 90% of the bones, including claws and a hip bone that spanned 45 inches across. The skull was never recovered but most other bones were found intact. 

Scientists identified the bones as from an extinct prehistoric ground sloth, Megalonyx jeffersonii, that lived close to13,000 years ago. The scientific name of Megalon, means great claw, and Jeffersonii is named for former President Thomas Jefferson who had a strong interest in fossils. 

Prehistoric environment

The ground sloth roamed the earth about 3000 years after the end of the Ice Age. The area had reheated and vegetation was beginning to fill in. The region was once dominated by forests, lakes, and bogs, an environment more commonly seen today in an alpine environment and provided a diverse food supple for large herbivores like giant sloths.

David B. Williams, co-author of “Spirit Whales and Sloth Tales: Fossils of Washington State” estimated the sloth weighed a little over a ton — about the size of a horse. The creature had a massive barrel chest and short stubby legs, was covered in fur, and had very long claws. 

“It was a large animal. It probably used those claws for stripping leaves or for digging. The advantage of being that big was that it made it harder to be eaten by predators,” Williams said. “At that time, you've got saber tooth cats, you've got dire wolves, you've got these big bears. Its size was part of its defense.”  

A sloth named Gordy 

Since 1977, the prehistoric sloth has had a permanent home at the Burke Museum.  Missing bones were cast in plaster by Burke scientists to create a complete skeleton. Pieced together, it stands 11 feet tall and is roughly the size of a Mini Cooper. In more recent years, the museum named the skeleton “Gordy” to honor Simmons and his discovery. 

Johnson said having the fossil named after him meant a lot to her father. “It was a dream fulfilled. When he was working with the crew who made the discovery, one of the men said, ‘You know what, Gordon, you have found the state fossil. They should name it after you.’ And I think that planted in his heart a desire to someday have that come true. When the Burke decided to do that, that was a dream fulfilled for my dad.”  

The museum gave Simmons and his coworkers replicas of Gordy’s claw to honor their role in his discovery. “We enjoyed having the little replica of the claw that they gave my dad to bring to show and tell when we were kids in elementary school. So that was kind of fun,” Johnson said.

Gregory Wilson Matilla, professor and curator at University of Washington said naming a fossil is uncommon, but some fossils are so complete or important that naming them is a way to create greater connection. 

“It's just a great story of someone paying attention and reaching out to the museum because he's interested in making sure the science is done and we have this great story,” Matilla said.

A story told just in time

 In March 2022 Long Beach Peninsula journalist Patrick Webb got a call from his editor Matt Winters at the Chinook Observer with a tip about Simmons’ story. Simmons was currently in home hospice care in Skamokawa, and this was the chance for him to tell his story one last time.

As a retired editor and freelance journalist, Webb often takes his time with stories before pursuing them. But something about the story resonated with him. It reminded him of the story of the Tyrannosaurus rex named Sue, the mostly intact skeleton at the Field Museum in Chicago. The fossil had been discovered by Sue Hendrickson in 1990 in South Dakota and named for her.  Acting quickly, Webb connected with Simmons’ daughter Johnson the same day and interviewed Simmons over the phone. 

“I was talking to him about the most amazing day of his life, but he said the most amazing day was when he married his wife (his high school sweetheart Irene),” Webb said. “As much as it could come through in that moment, his voice was alight with enthusiasm. It was quite clear that this was his claim to fame. Even though there was weakness in his voice, it was bubbling with enthusiasm.” 

Knowing Simmons’ health was poor and wanting him to have the chance to read his story, Webb and Winters hustled to get the story out and published it online as soon as possible. Once the weekly newspaper hit the presses, Webb and Winters had a few copies delivered by Express Mail to Simmons’ home on March 25. Simmons passed on March 27, but Johnson confirmed he was able to read the story in the days before.

“Newspapers hustle to get stories for a plane crash or fire and post them online, but this was a feature story,” he said. “I’ve been in this business 48 years and no feature story have we ever hustled to get online so quickly.”

A natural storyteller, Simmons never tired of sharing the story of his sloth discovery with family and friends, including his wife, five children, nine grandchildren, and four great grandchildren. He remembered every last detail and the story has become a family and community legacy.

“It was a classic case of a regular guy and something exceptional happens to him. A guy who is a sports starter in high school and marries his high school sweetheart.  He works in construction and one time, something exceptional happens to him,” Webb said. “He delights those in this family and those around him by relaying these treasured memories. 

Beyond the memories the sloth was named after him. It’s a story that he doesn’t have to exaggerate; it’s the truth. He found a fossil that was named after him. It’s 12,000 years old. It wasn’t just his family that thought it was a big deal. We have scientists saying ‘every time I do a (Burke Museum) tour, I point out this fossil because it’s so cool.’ The story is a delight and captures people’s interest.”

See the sloth for yourself! Check out Gordy at the Burke Museum on the University of Washington campus or see a replica at the Highline Heritage Museum.

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