Oct. 21, 2009 -- Patty Wetterling is getting ready for an anniversary no parent should ever have to mark: It has been 20 years since her oldest son, Jacob, 11 at the time, was snatched away from her in one brutal instant.
Over the past two decades, Wetterling has sustained herself with hope.
"We hope for Jacob, for all of our grandkids, for every child who's home safe today and every child who's missing," she said in an interview with "Nightline."
Wetterling and her husband, Jerry, their three other children, and three grandchildren were gathering at their rural St. Joseph, Minn., home in the lead-up to the anniversary. The family considered the milestone a chance to honor Jacob.
"We learned early on that this, what happened, was way bigger than Jacob and way bigger than our family," Patty Wetterling said. "It's about [like] this entire community was taken. There was an innocence stolen and my hope is that we have been able to pull some of that back and to provide, you know, this world where kids can grow up safe."
ABC News first made contact with Wetterling 10 years ago.
"This is God's country," she said at the time, walking in a cornfield just a half-mile from her house.
It was through the same fields, on a warm autumn night, that Jacob, his brother Trevor and a friend set out on their bikes to pick up a video.
It was the first time Jacob had been out alone at night on his bike.
On the return home, according to the other boys, a masked gunman stopped all three -- and then drove off with Jacob.
On a gravel road was a spot where Jacob's footprints seemed to show resistance. And then...
"It's gone," Wetterling said. "It's just bizarre."
It was just the beginning of a nightmare from which Wetterling has not yet awoken. But something inside her has awoken.
Over the years, Wetterling has found her voice, and her mission: to find Jacob and help protect other children.
"A lot of people ask, 'How do you do it?' How could I not?" she said. "Every parent knows, you would do anything for your children, and our anything [has] got to be a little more than we ever would have dreamed, but you continue. We'll do anything that we can to find him."
Jacob Wetterling's Family Holds on to Hope 20 Years Later
Wetterling has started a foundation in Jacob's name. And 15 years ago she helped pass a bill that requires states to implement sex offender registries. She works closely with the National Center for Missing and Exploited Children, which attempts to track the approximately 100 children a year who according to Justice Department estimates are abducted by strangers.
Ernie Allen, head of the center, says that the chance of finding missing kids diminishes with time, but that hope must not. Children do come back, he said.
At the children's center, experts can project what a child will look like as he or she ages. Such a photo turned out to be strikingly accurate when Jaycee Dugard was found in California 18 years after her abduction.
What might Jacob Wetterling look like now, at age 31?
His mother said it's hard for her to look at the projection images.
"It's hard for me to look at those, because that's not a real person," Wetterling said. "I remember Jacob, and that's a drawing. So, as a mom I know they know what they're doing, but I don't relate to the age-enhanced photo."
She does, of course, relate to other searching families and has met some whose missing loved ones have miraculously returned.
In 2007, she met Jessyca Mullenberg, a girl from rural Wisconsin who, at age 13, escaped the former teacher who had held her captive for more than three months.
"I love Jessyca," Wetterling said. "She's, you know, got that survival skill. She made it. I wish that it had never happened. But she made it through a really horrific situation, and there are kids like that. And I just think they're our heroes."
For Wetterling, Jessyca Mullenberg embodies the possibility that even long-vanished children may still be alive.
"We can learn from this case that these kids can come home, and we know that kids have come home after six months, nine months, two years, four years, 11 years," she said.
In one of the most remarkable cases of its kind, Jaycee Dugard was reunited with her family after 18 years of captivity.
'I Think About Him Every Day'
"When Jaycee was found, it was just this exclamation point to our statement," Wetterling said. "There are missing kids out there, it's our job to find them and she did it. She survived some really horrible things and she did it."
Jaycee was on the cover of People magazine, her smile amazingly similar to her smile as a child.
"She is beautiful and she looks so deep-down happy and that's a great starting point," Wetterling said. "And no matter what happened in between, nobody could take away those first 11 years and she drew energy from that, that unconditional love."
As for Wetterling's son Jacob, there are fewer leads each year. But the Wetterlings hang on. Since Jacob vanished they have not changed their phone number, or moved, in case he tries to contact them.
What gives her the ability to keep going and keep hoping?
"How can I not? How could I look Jacob in the eye?" she said. "If I believe that he's alive and some day he could come home, how could I just look him in the eye and say 'I wanted to believe, but you know, I got kind of tired.'"
This past weekend, Wetterling helped organize a concert at a nearby college. It was not a memorial, but a celebration of children, she said.
"I want [students] to walk away uplifted and feeling wonderful about the good people in the world, and the hope and the promise that children give to us and that we can return the gift to them," Wetterling said.
One of Jacob's favorite singers, Red Grammar, performed.
And Wetterling read from a book she's written for her three grandchildren.
Some of Jacob's old friends and classmates came. They are grown now, many with their own children.
"I think about him every day," Wetterling said. "I do. I just say a little prayer and try and send out some energy to let him know I'm still searching. ... I believe there's a possibility.
"My hope has broadened," she said. "You know often, I'll be shopping in a mall and people see me and they'll grab their other kids real close. It's very subtle but they, I represent something no parent wants to think about."
'It's Been So Long Now'
While the Wetterling family hasn't given up on Jacob, they also haven't given up on life. Trevor's got a career, a wife and a son named Jacob. They call him Jake.
"He represents potential and the future, and he's got a tremendously big smile and it's like 'Hello world,' you know," Wetterling said. "It's absolutely wonderful, it brings it all back, that's who we were, that's what we believed in. I'm so very proud of our children and how they've managed to go forward and not be cynical or fearful or you know, just stuck. But they've managed to find wonderful people in their lives and build these wonderful families, and we do laugh again and enjoy.
Still, Trevor, like his whole family, said he has an unshakable need for answers.
"It's been so long now, and I just want to know what happened," he said. "I mean, I really want to."
Is he as sure that Jacob is alive as his mother is?
"I have no reason to believe otherwise," he said. "So until there's something else that's going to change my mind, I mean, I'm going to still believe that he's out there somewhere."
Yellow ribbons no longer hang in the streets of St. Joseph. There have been milestones missed -- birthdays and graduations. But in a house on the edge of town, one family still stands vigil for the boy who just wanted to ride his bike to the corner store on a warm autumn night 20 years ago.
"We have no proof to show he's not coming home, and so you hope," Wetterling said. "To me, hope is a verb. You don't see us back with our feet up, 'You know, I hope he comes home.' You know, you get out and you do things to make it happen.
"I will not let the person who took Jacob destroy my mind as well, and my hopes and my beliefs. He can't have it.
"So you never give up," she said. "As a searching parent, you just never give up on your child, ever."