Cherrie Mahan was 8 years old when she vanished while walking from a bus stop near her home in the rural community of Winfield Township, Butler County.
Cherrie Mahan has been missing since 1985.
A picture of the smiling, brown-haired girl would be the first featured on direct mail fliers like those now sent weekly to tens of millions of U.S. homes with a simple message -- "Have You Seen Me?"
Monday marks 25 years since Cherrie disappeared. Although she has never been found, the fliers are credited with helping to recover 149 other missing children, according to the National Center for Missing and Exploited Children.
"It emphasizes the point that somebody out there knows," said the center's president, Ernie Allen, who also told Channel 4 Action News by phone that Cherrie Mahan's case is one that still haunts him.
"The worst is simply not knowing," he said. "Twenty-five years later, the search goes on. The file is still open."
The idea for the fliers came after advertising executive Vincent Giuliano saw a television movie about the 1981 murder of 6-year-old Adam Walsh, who had been abducted from a Florida shopping mall.
The next day, Giuliano and employees talked about the show, and the idea of putting pictures and a hot line number on their mailers began to form. Giuliano was so moved that he arranged to meet Adam's father, John.
Cherrie was chosen for the first flier in May 1985 because there were enough details about her case that the center figured someone had to know something, Giuliano said.
The third-grader got off her school bus the afternoon of Feb. 22, 1985. A driver saw Cherrie get off and noticed a bluish-green van with a painting of a mountain and a skier on it behind the bus. But as the bus stopped to allow traffic to pass after driving down the road a bit farther, the van had disappeared.
Cherrie's stepfather told police he had let her walk the short distance home because it was a nice day. When she didn't arrive, he went to the bus stop 10 minutes later and saw tire prints, but no Cherrie.
Giuliano said it's "so bewildering" that someone who knows something about the case hasn't come forward.
"Cherrie is a child I'll never forget, and it literally haunts you that that's the child you didn't bring home, the child you didn't find," Allen said.
State police said they haven't closed the case, just in case someone does come forward.
If Cherrie Mahan is still alive, she is now 33. Posters have been made to show an age progression of what she may look like today.
While her case serves as a reminder that not every missing child is found, the flier program has had success and gives hope. More than half the 2,100 children featured on the fliers have been found through other means, such as police investigations or other groups posting pictures of them.