Rebekah Martinez, left, was reported missing in Northern California, but she’s been a prominent contestant on the ABC series “The Bachelor.” ABC

When the North Coast Journal, an alternative weekly newspaper in Northern California, posted a story to Facebook about 35 people who were reported missing in Humboldt County, it asked its readers if they recognized any of the faces.

Amy Bonner O’Brien, who has lived there for 25 years, couldn’t believe what she was seeing.

“Yep, Rebekah Martinez is on this season of The Bachelor,” she wrote in a Facebook comment to the newspaper, swiftly solving the mystery.

Indeed, Ms. Martinez, a 22-year-old contestant on the current season of ABC’s reality show “The Bachelor,” was reported missing by her mother on Nov. 18, about a month and a half before her season would premiere on Jan. 1, according to the Humboldt County sheriff’s office.

And she was still considered missing, despite nationwide celebrity and active participation on social media, until Thursday, when Ms. Bonner O’Brien and others alerted the local sheriff’s office.

The confusion boiled down to several strands of miscommunication.

Her mother filed the report at about 1 a.m. on Nov. 18, saying she last had contact with her daughter on Nov. 12.

The mother heard from Ms. Martinez late in the afternoon on the same day she filed the missing person report, the sheriff’s office said. But investigators didn’t learn that until Dec. 12, when a deputy sheriff contacted the mother by email to follow up.

Still, investigators were unable to get in touch with Ms. Martinez.

“As part of procedure, Humboldt County Sheriff’s Office deputies are typically required to make direct contact with the missing person to confirm status and well-being, as geographical and other factors allow,” the sheriff’s office said in a statement. “A deputy was not able to make direct contact with Martinez and she was not removed from the Missing and Unidentified Persons System.”

On Thursday, after the newspaper article was published, a deputy again tried to contact Ms. Martinez by phone, the sheriff’s office said. The deputy spoke to the mother, who said Ms. Martinez had tried to contact the office but was unable to speak to a deputy.

Finally, at 2:59 p.m. on Thursday, Ms. Martinez returned the deputy’s call, confirming she was alive and well. She was removed from the system, the sheriff’s office said, though her missing person’s report remained online until Friday afternoon.

All the while, Ms. Martinez has been publicly active on Instagram and Twitter. After writing on Sept. 17 that she was giving up social media for “the next several weeks” — a time that corresponds with the filming of “The Bachelor” — she began posting photos on Instagram again on Nov. 22.

She is one of nine women who remain in contention for the affections of Arie Luyendyk Jr. on the television show, and she was unavailable for interviews on Friday. But she did address the report on Twitter:

Ms. Martinez has been one of the more prominent personalities on the show, gaining attention even before the season started as the first contestant in the show’s 21-season history to have a pixie cut. At 22, she was the show’s youngest contestant, and her 14-year difference with the bachelor, Mr. Luyendyk, has been a prominent point of discussion among fans and fellow contestants.

Ms. Bonner O’Brien said Friday that she wasn’t a big fan of “The Bachelor.” She had only watched the premiere episode of the current season, with another on in the background once while she was cooking.

But that was enough to recognize Ms. Martinez in the North Coast Journal article because she “has a distinguishable look compared to the other contestants,” she said.

“If it was any of the other girls, I wouldn’t have thought twice,” she said. “But she has the short hair.”

While her sister has taken to calling her “Sherlock Holmes,” she insisted she wasn’t much of a detective.

“It really wasn’t that hard to figure out,” she said. "I’m surprised no one else noticed.”

Thadeus Greenson, news editor at the North Coast Journal, said Friday that Ms. Martinez wasn’t the only person who didn’t belong on the missing persons list. As Linda Stansberry reported the story, she found others on the list whose social media presence made clear they were alive and well. Another man called the newspaper on Thursday, shocked to see his name on the cover.

“I think between what Linda found pre-publication and what’s happened afterward, it’s at least four or five people who were going about their everyday lives with no clue they had been reported missing,” he said.