Missing Oregon Girl: Kami Vollendroff, 16, disappeared in November 2001

(CBS) Kami Vollendroff of Stayton, Oregon, has been missing since Nov. 21, 2001, when she vanished along the Oregon coast at Boiler Bay State Park, near Depoe Bay. Kami was three weeks shy of turning 17 when she disappeared.

Pictures: Oregon teen girl missing since 2001

Authorities believed Kami and her boyfriend, who state police identified as Eugene Hyatt , 18, were swept out to sea by a powerful wave, while walking during a storm.

According to the North American Missing Persons Network, the couple had been staying at a condominium belonging to Hyatt's grandparents, and told them they were planning to look at tide pools during the day.

"Evidently they (police) think that a wave washed them off into the ocean," according to Kami's grandmother, Ruby Peevey. But, Peevey told Crimesider, "The coast guard told us it was so rare for two people to go in the water, and not one body come back out."

Three years later, there was a new development.

A picture surfaced that Peevy thought looked an awful lot like her granddaughter.

The picture of a young woman had the words "naughty or nice" across it, as well as "very open minded and discreet."

"The grandmother herself felt for a long time that perhaps these kids had drowned...then she called me and said you gotta get up here because I got this picture, you're simply not gonna believe it," said Gregory Mengell, an investigator with the Interstate Association for Stolen Children.

Mengell said he sent the picture to the National Center for Missing and Exploited Children who looked at it, too, and "they were certain it was her (Kami) as well."

"They computerized the pictures and it had come out 99.9% that they were the same person," said Kami's grandmother.

While it's tempting to think that perhaps Kami was swept out to sea, Mengell says, "she probably was not washed out to sea. I feel she's a victim of some type of foul play."

Born Dec. 12, 1984, when she disappeared Kami Vollendroff was 5'7" and about 130 lbs. She was last seen wearing shiny black pants and a white sweatshirt.

If you have information about Kami's whereabouts, contact the National Center for Missing and Exploited Children (NCMEC) at 1-800-843-5678, or the Lincoln County Sheriff in Oregon at 541-265-4231.