Now, the Bish family has decided to throw themselves into activism, and do all they can to keep alive the hope that they'll find their daughter as well.
At one event for missing children, they even met the parents of another missing blond teenager -- Elizabeth Smart -- and began corresponding. Like the Smarts, the Bish family couldn't sit back and expect the police to do it alone.
John Bish makes regular pilgrimages to Comins Pond, and he has his own theory of what happened.
It goes back to the morning before Molly vanished, when Magi Bish saw a man sitting alone in a white car in the parking lot. She waited nervously for 20 minutes, until the man drove off. Then, Magi says she put the incident out of her mind until the next day.
"The man had dark hair, kind of, salt and peppered though he was. Between maybe 45 and 55," recalls Magi Bish. Police have released two composite sketches.
Police discovered that Magi Bish wasn't the only one who'd seen a white car in the vicinity. Other witnesses also spotted a white car – first, near a car wash at the base of Comins Pond road. And later, at the end of a trail from the beach to the cemetery.
John Bish says the scene itself provides telling hints as to exactly what happened next, starting with that open first-aid kit: "I think this was just someone who said, 'I need a band-aid. I've cut myself. Do you have something?'"
Then, after Molly turned to open the kit, John thinks the kidnapper forced her up the cemetery trail, since her shoes were left behind. He says she'd never voluntarily have gone barefoot up that hill.
District Attorney John Conte pursued the white-car theory seriously, and his team did a cursory search of 125 white cars. But his investigators believed the abductor had to live nearby. They began interrogating local sex offenders.
At least one of those questioned, a convicted child rapist named Oscar Baillargeon, bears a striking resemblance to the sketch. He's also admitted to meeting Molly at a party. But Magi Bish had doubts: "Definitely there's resemblance, but it's, the hair wasn't."
The sketch has become one of the most recognized drawings in Massachusetts. But police have never identified the "white car man." "We've got over 4,000 leads in a database," says Conte. "We're looking for evidence. We don't have it."
Three years after Molly Bish disappeared, a piece of Molly's clothing was discovered on a wooded hillside, five miles from the pond where she vanished. It's the first major clue in the case.
But the big break comes from a local ex-cop named Tim McGuigan, who had an obsession with an entirely different crime - the abduction of another young girl from the area.
In August 1993, Holly Piirainen, 10, went walking along a country road near her grandmother's house in Sturbridge, Mass., and simply vanished. All searchers found was one small shoe.
In the following weeks, Holly's parents, Richard and Tina, and grandmother, Maureen, went through the same ordeal the Bish family would experience seven years later. Ten weeks after she vanished, local hunters discovered Holly's remains in the woods nearby.
"The worst part of it for me was wondering who it was who did this to my daughter," says Holly's mother, Tina.
Investigators were never able to figure out who killed Holly Piirainen. But several years later, McGuigan couldn't get Holly's unsolved murder out of his mind: "I thought of the innocence of this child and her life taken away by a predator. It made me realize there's real evil out there. There's evil out there. And I wanted to do everything I could do to help her."
McGuigan started his own investigation, but he says his superiors were not sympathetic.
"What's bigger in life than getting a predator off the street before he grabs somebody else," asks McGuigan, who admits that the case began to take over his life. He started drinking heavily, his marriage fell apart, and in August 2002, he left the force and drifted from job to job.
While writing a true crime account of Holly's murder, McGuigan became increasingly fascinated with its similarities with the Molly Bish case. They were both two young blonde girls who vanished in a rural area, just a few miles apart. McGuigan now went to the Bishes asking for permission to investigate Molly's case as well.
Two weeks later, police made a startling announcement. They discovered pieces of a weather-beaten bathing suit, much like the one Molly Bish was wearing. McGuigan discovered the suit, and he says a local hunter, Ricky Beaudreau, led him to the site.
Beaudreau says he had actually seen the blue suit months earlier, but he'd forgotten about it until he crossed paths again with McGuigan. The bathing suit was sent to the laboratory and another intensive ground search began.
"We want to solve this case, and we want to find Molly, and we want to bring her back to the Bishes," says Conte.