It's not unusual for an archaeologist to get stuck in the past, but Carl Gustafson may be the only one consumed by events on the Olympic Peninsula in 1977.
Sifting through earth northwest of Seattle, he uncovered something extraordinary - a mastodon bone with a shaft jammed in it. This appeared to be a weapon that had been thrust into the beast's ribs, a sign that humans had been around and hunting far earlier than anyone suspected.
Unfortunately for Gustafson, few scientists agreed. He was challenging orthodoxy with less-than-perfect evidence.
For almost 35 years, his find was ridiculed or ignored, the site dismissed as curious but not significant.
But last month, a team that re-examined his discovery using new technology concluded in the prestigious journal Science that Gustafson had been right all along.
The pierced bone was clear evidence that human beings were hunting large mammals in North America 13,800 years ago - about 800 years before the so-called Clovis people were thought to have migrated across the Bering land bridge from Asia.
The announcement came as sweet vindication for the now-retired Washington State University professor.
"I was pretty bitter about the whole thing for a long time," Gustafson, 75, recalled. "I don't like saying it. I never really admitted it except to my wife. It was so frustrating. But I'm very humbled and happy it turned out this way."
His discovery has helped redefine our understanding of the history of the Americas.
It started in 1977 in Sequim, Wash., when a man turning over dirt with a backhoe unearthed what looked like the tusk of a mammoth.
A week later, Gustafson heard about the find. There, in the earth, he found the bones of a mastodon, an elephant-like creature that went extinct about 11,000 years ago. Within hours Gustafson found the rib bone with an odd fragment in it.
The rib bone was sent to be X-rayed. The dating suggested the bone was 14,000 years old, but the margin for error was high. The X-rays showed what looked to be a projectile point, but it was blurry.
Still, Gustafson believed he'd stumbled upon a game changer.
Since the 1930s, many scientists had come to believe it was unlikely that humans in the Americas predated Clovis people. For starters, there was a lot of evidence of Clovis people, but nothing credible had surfaced to suggest humans were here earlier.
Gustafson's find was called inconclusive, or simply reinterpreted. The "weapon" was probably just a piece of tusk left behind by another mastodon after a fight, some said. It could have been a broken antler from a charging elk, others argued.
"It was just so frustrating," Gustafson said. "I had all this stuff, all this information."
He just lacked important modern tools.
