UNIDENTIFIED FEMALE: And her body was found on just the other side of this rock.

GRIFFIN: And if not for this historian, turned amateur sleuth, it would have ended here. A mysterious young woman, found on the banks of Boulder Creek by two college students. She was badly beaten. And the coroner believed she was still alive when she was tossed over the side. The woman, thought to be about 20, probably died of exposure.

It was snowing the week they found Boulder's, Jane Doe. The week of April 22, 1954.

UNIDENTIFIED FEMALE: But this is filed under murders.

GRIFFIN: It was Silvia Pettem, a Boulder, Colorado historical writer, who found this Jane Doe for the second time, actually walking past a simple grave in the city's oldest semiterry.

SILVIA PETTEM, HISTORIAN: No one came forward. She -- there was no one reported missing that matched her description, so she was a complete mystery.

GRIFFIN: Boulder's Jane Doe would be about 70 now. Her mother, probably dead. And now, another mother is looking out for her.

PETTEM: If this were my daughter and we didn't know where she was, or who she was, I can't even image what's that like for a family. So, I guess it's the mother coming out in me.

GRIFFIN: With the help of the police, Pettem is on her way to solving this case. It's an investigating path that has led Pettem to another discovery, her Jane Doe is hardly alone. There are thousands of them.

(on camera): Were you surprised how many of these cases like this were out there?

PETTEM: Yes. Absolutely. When I first got interested in this case, I had no idea that other people across the rest of the country were doing the same thing.

UNIDENTIFIED MALE: This lady was found, alone, in Tempe, Arizona.

GRIFFIN (voice-over): Todd Matthews had that same reaction when he took his case online. That was seven years ago.

TODD MATTHEWS: I had no idea that there was another Jane Doe until I went online. You know, this is the only one I ever heard. It was unusual to me.

GRIFFIN: He lives thousands of miles from Boulder, in rural Tennessee. But Todd Matthews is tie by the Internet to Silvia Pettem and many other volunteers across the country and around the world. Their mission, return names to the dead.

Since 2001, that mission has been called The Doe Network.

(on camera): These people want their names back.

MATTHEWS: Of course, of course. I always hesitate to say haunting, but you do feel that pull and you know when you have done a good thing. You get that feeling of satisfaction that comes from inside of you. And, you know, it's almost like a blessing.

GRIFFIN (voice-over): Matthews first felt that blessing when he identified his own Jane Doe.

MATTHEWS: That was her. Barbara Taylor. And that's a picture of my father-in-law.

GRIFFIN: His father-in-law, Wilbur Riddle (Ph), found the girl's body even before Matthews was born. Riddle (ph) spent decades trying to learn who she was. When Matthew's married into the family, he carried on his father-in-law's mission. And in 1998, he solved the mystery by putting the case on the Internet. .

MATTHEWS: The Internet was evolving and becoming an actual resouce. That's when they were just popping up on little lights coming on at dark. Just when I thought this was all of them, there was more, there's more and there's more. And it just seemed like it never stopped. And it's still like that today.

GRIFFIN: Today, Todd Matthews, along with others, runs The Doe Network, a growing Web site, a database, filled with mysteries.

According to law enforcement records, nearly 6,000 bodies across U.S. and Canada are known only as Jane and John Does. The Doe Network has listed 2,000 of those cases, some murdered, others die naturally. But all missing their names. And since 2001, The Doe Network's volunteers have helped solve more than 30 cases.

Boulder's Jane Doe would be next.

PETTEM: She was completely naked. She's been stripped of everything, all jewelry, all identification. She had three bobby pins in her hair.

GRIFFIN (on camera): Severely beaten, a fractured skull, and for the past 51 years that's all anybody knew about Boulder's Jane Doe found on this rock in 1954. But her case has again, rekindle the community that buried her. Boulder's Jane Doe is now an active murder investigation. They're not just trying to find her name, but her killer.

(voice-over): And it is Pettem's work that has led the way. She did the work to reopen the investigation. She raised money to paid for the body to be exhumed. There is now DNA to compare to any living relative.

PETTEM: We know more about this girl today than we did 50 years ago when she was buried.

GRIFFIN: And later this month, what she hopes will be the major break, forensic experts will produce a facial reconstruction next week, similar to this one. Silvia Pettem and Boulder will be able to see what Jane Doe looked like the day she died, a photo of that face will immediately be placed on the Doe Network Web site. And Pettem will wait for the call that may finally place a name on this grave.

PETTEM: Everybody deserves a name. Certainly, no one should be buried for 50 years with Jane Doe on their stone. And some people are buried without a stone at all.

(END VIDEOTAPE)

ZAHN: Drew Griffith reporting. According to the Doe Network's Web site, there are now over 400 volunteers working to help solve nearly 3500 unidentified victims and missing persons cases.