YAKIMA — Joe Sebille was hiking alone in the North Cascades one afternoon last October when he rounded a bend and came face-to-face with a little piece of history: the first grizzly bear verified in the Cascades since 1996.

Only he thought it was something else.

“I’d been up there three days before and there had been three black bears, almost at that exact spot,” said Sebille, a 26-year-old small-equipment mechanic from Mount Vernon. “There’d been all these people around that time, maybe 50 other people, so I felt really safe.

“This time I was by myself and I came around the corner and boom, there he was.”

Sebille was at about 6,500 feet elevation outside of Marblemount in the Cascade River area of eastern Skagit County. When he saw the bear, it was silhouetted against the afternoon sky and clearly unaware of his presence, having not heard his “bear bell” — designed to alert animals or other predators to his approach — hanging from his day pack.

So he shook the bell.

And the bear looked up, right at him.

“When we made eye contact, it was intimidation city,” Sebille said. “Then he went right back to what he was doing before, sniffing around or eating or whatever. I would like to think he snorted, but I don’t even think he made a noise. He just went right back to what he was doing.”

So Sebille pulled out his cellphone and took a picture. And then four more.

And he had no idea what he had.

“I guess maybe I should have known it was a grizzly, but grizzly bears are only supposed to be rumors in Washington,” he said. “I knew about the five-and-15” — a reference to published estimates of five to 15 grizzlies presumed to be living in the North Cascades — “so I just figured it had to be a black bear.”

Later, a friend looking at the photographs mentioned something about the hump of the bear, Sebille said.

“That set off flags in my mind immediately. And I noticed it had a dished face, so I knew I should have realized what it was.”

In May, Sebille shared the photographs and his story with officials at North Cascades National Park. When park service bear biologist Anne Braaten saw the photos, she knew what they seemed to be and called Sebille for more information. She then shared his account with members of the North Cascades Grizzly Bear Subcommittee of the Inter-Agency Grizzly Bear Committee. They agreed, and so did a group of grizzly bear experts who subsequently viewed the photograph: Sebille’s photos were definitely of a grizzly.

There have been numerous sightings of grizzlies in the Selkirk Mountains, which span from northeast Washington into British Columbia and Idaho, and one grizzly was seen several years ago in the Okanogan Valley highlands. But this was the first verified sighting in the Cascades in 15 years.

“This is huge,” said Joe Scott of Conservation Northwest, located in Bellingham. “This is, I think, one of the biggest conservation stories of the last couple of decades. The fact that the government is excited about it, too, is encouraging, because hopefully now they’ll initiate recovery actions. Even though we have a bear there, and it’s such a rare sighting, we probably don’t have a viable population without some kind of proactive recovery actions.”

Bill Gaines, a biologist with the Okanogan-Wenatchee National Forest, is leading a study in the North Cascades, using barbed-wire corrals with bear-attractive scents in the middle; when a bear enters the corral, it leaves hair on the surrounding fence that can later be DNA-tested.

Researchers believe being able to identify individual bears through DNA samples will help determine how many grizzlies are in the North Cascades, how they are related and whether they are producing.

Doug Zimmer of the U.S. Fish and Wildlife Service called Sebille’s sighting “a classic example of why people should contact us if they think they see a grizzly bear.”

“The importance of this is it proves there are grizzly bears still up there, and it reminds us the work we’re doing on grizzly bear recovery is working and is important and needs to go on,” he said.