Against all the odds, rescuers found an 18-year-old autistic man in West Virginia woods who had been missing for four days. Jacob Allen was hiking a little ahead of his parents in the Dolly Sods Wilderness last Sunday when they lost sight of him.

"I turned and made visual contact with Jacob up the slope ahead of me and started calling, telling him to wait," said his mother, Karen. "I saw him make the bend in the trail to the left, which was where the trail went, and at that point it was very defined with thick rhododendrons. So I told my husband, 'I've got to catch up with Jay. He's not really slowing down much.' So I got to that bend he was nowhere in sight."

They continued to hike upwards, frantically looking for their son and calling his name. But when his mother reached the top, she did not see him and panic set in.

Their deepest fears would have been justified for any child that went missing in the woods without food or water, but Jacob was up against other odds. Because of Jacob's autism, he couldn't call out for help, shout out his location or even answer if anyone called his name.

"The minute he gets out of your sight," Karen said, "it doesn't matter where you are because ... he doesn't respond verbally. He understands language, but if I call his name, he's not going to say, 'I'm here' or 'I need help,' and might not even make a sound."

Whitney Davis, an education graduate student and family friend of the Jacobses, was employed for several years to help train Jacob in various skills. She taught him how to communicate by stringing together pictures of various things and actions. She worked with Jacob and his family to create a book including pictures of actions and physical feelings that he could point to, to communicate with his family.

But none of that could help him out there in the hills and by Wednesday this week, there were hundreds of people organized in search parties. Davis, who had joined the search party, was stunned by how difficult the terrain was and how thick the brush was.

"It was very rocky so there's huge rocks and crevices," Davis said. "And when they say that you can't see five feet in front of you, you can't see five feet in front of you."

She thought to herself, "If Jacob is in here, I don't know if we'll ever find him."

But among the thick brush, volunteer Jeremy Reneau was able to find Jacob. Reneau had heard about the story on the news and decided to help out because he knew the area well. He found Jacob lying down on the ground.

"I was just coming through a big thicket of laurel and I looked over to my left and then there was a little clearing about 10 by 15 feet and I saw him lying there," he said. "I went over to him, I called his name. When I was closer to him, I called his name again and he opened his eyes and rolled over to me."

Losing sight of an autistic child is a nightmare that every family with such a child is forever fending off. However, it happens with frightening frequency.

In 2005, a policeman in Orange County spotted a 13-year-old autistic boy walking on railroad tracks. Louie Perales, whose autism prevented him from speaking, had wandered off from home and was walking on the tracks as a freight train barreled toward him. Luckily, the police officer was able to pull the teenager off of the tracks before the train hit him, and Louie returned home unharmed.

Unfortunately, this isn't always the case. In June of 2006, a 7-year-old autistic boy drowned to death in a closed city swimming pool in Baltimore when he wandered off from his elementary school and jumped in.

With such risks, some may wonder why the Allens took their son on a hike in the mountains in the first place, but they feel going out in nature is not only good for their son's development but it is an environment where he thrives.

"Jacob loves the outdoors," his mother said. "Jacob's behaviors have, I think, moderated over the years. One reason is, I think, because we do get him out so much. And he's learned many, many things from being outdoors -- riding bikes, he's learned about dangers, his body. ... That may actually be his place of choice. Exactly where he functions best."

To families like the Allens, the risks associated with such activities might well be worth taking. But to lessen the chance of losing a child, police forces in at least 42 states have implemented a program that assists them in finding autistic children and other people with special needs who go missing.

The program, called "Project Lifesaver," allows parents to register their children and has them wear a battery-operated radio wrist transmitter. The transmitter emits a silent tracking signal every 24 hours that police officers can track if a child is reported missing.

New Jersey Sheriff Leo McGuire believes that with the technology, the Allens could have found their child in minutes instead of days.

"We would have been able to bring that kid home sooner than four days," McGuire said. "Instead of looking for a needle in the haystack, you have a beacon saying 'find me, find me.'"

The Allens say they will take more precautions with their son on their next hike. They plan to bring someone along younger than themselves who can keep up when their boy -- who loves nature -- charges ahead.