Pettem's goal of giving Jane Doe back her real name and returning the remains to her family seemed more reachable Monday when the Boulder County Sheriff's Office unveiled a painstakingly reconstructed likeness of the young woman.

Pettem learned about the case in 1996 when she participated in a "Meet the Spirits" reenactment at Columbia Cemetery in which volunteers portrayed the dead. Her character was a university professor, but a nearby tombstone caught her eye. It read: "Jane Doe - April 1954 - Age about 20."

"I often went to the cemetery. I would always pass her grave. The more I saw it, the more I wondered about it," Pettem said.

The woman's naked body was found by University of Colorado students beside Boulder Creek nine miles west of the city on April 8, 1954. She had been badly beaten and thrown down a 29-foot embankment.

She was blonde and in her late teens, with an appendectomy scar and perfect teeth. But she was unrecognizable after four to 10 days of exposure.

"I call myself a historical detective," said Pettem, who lives in the mountains west of Boulder with her husband, geologist Ed Raines.

The sheriff's office files had disappeared, so Pettem began researching the case in newspaper files.

In 2003, she went to the sheriff's office to ask that Jane Doe be exhumed. She then started a fund to raise money for the project.

Her inquiries eventually led to the Vidocq Society, a group of forensic experts in Philadelphia who help police solve cold cases.

"They jumped in," Pettem said.

Walter Birkby, of Tucson, Ariz., carefully reconstructed Jane Doe's skull from fragments. Frank Bender, one of the Vidocq Society founders, fashioned a likeness of the face in reinforced plaster.

Bender said such likenesses are "a balance of art and science." He's worked on dozens of such projects, and at least 40 ended in identifications.

Sheriff Joe Pelle said the bust unveiled before the news media might be recognizable by family members.

"It's a hope that some day every aspect of this mystery can be solved," Pelle said. "Maybe we'll find out who killed Jane Doe, and why and how.

"I realize that that's a longshot. At this point, though, it would be highly satisfactory to simply identify this young lady and to give a family, maybe, some closure."

DNA from the bones has enabled detectives to rule out two women who disappeared about the time Jane Doe was discovered.

A missing Nebraska woman's face does not fit the skull, but detectives want to do a DNA test of her relatives to be sure, Pelle said.

"I'm a mother and now a grandmother," Pettem said. "I can't imagine what it would be like to lose a daughter and not know where she was."