A woman who was abandoned in an Upper West Side phone booth as a newborn is searching for her birth mother.

The woman, who does not want to be identified for fear of interference by meddling pranksters, posted fliers near the booth in which she was apparently found on July 17, 1965, requesting anyone with information on her case to come forward. Pamela Slaton, a longtime friend who is fielding the phone calls, tells us they're in touch with the passerby who found her—before she was turned over to social services, and eventually, adopted—and that she's hired a private investigator.

Still, details remain thin—partially due to lack of information, but also because Slaton said she's reluctant to reveal any identifying characteristics that could sully the search. (And probably also because the ordeal is being filmed for a show on ABC, Slaton said.)

"We just want to keep this as authentic as possible," she said, adding that the baby was left in good condition, along with two objects that Slaton would not reveal. "Anyone who knows her will know what they are."

The sign indicated the woman would be at the corner on which she was found on July 15, though West Side Rag, who first noted the sign, reports she "did not show up because of the weather."

Still, Slaton said that for the woman, whom she met at an adoption support group, the real motivation for finding her birth mother is actually to thank her.

"Somebody must have watched to make sure she was safely picked up," she said. "She's a native New Yorker, she grew up here, and she is very happy in her life."