Butte, Montana (CNN) -- Five years ago, Leo McCarthy lost his 14-year-old daughter, Mariah, when a drunken driver hit her and two of her friends as they walked down a sidewalk near her home.
But he refused to let her tragic death become just another statistic.
Knowing that the driver was 20 years old -- not even old enough to drink legally -- McCarthy made an unusual promise to the teenagers attending Mariah's memorial service in Butte, Montana.
"If you stick with me for four years," he said during her eulogy, "don't use alcohol, don't use illicit drugs but give back to your community, work with your parents and talk to your parents, I'll be there with a bunch of other people to give you money."
McCarthy has lived up to his end of the bargain. Along with Jimm Kilmer and Chad Okrusch, the fathers of Mariah's two friends who survived the accident, McCarthy has given $1,000 scholarships to more than 140 high-school graduates who have taken Mariah's Challenge.
"I wanted to give them encouragement and to tell them that ... you can be better and always be greater in the situation," said McCarthy, whose nonprofit raises the money through private donations.
Mariah's Challenge is simple. Teens can go online and sign a pledge to not drink until they are 21 and not get into a car with someone who has been drinking. Toward the end of their senior year, if they have not been convicted of underage possession of alcohol, they are eligible to submit a scholarship application, which includes a 300-word essay explaining how Mariah's Challenge has affected their life.
Recipients are selected by McCarthy, Kilmer and Okrusch based on the essay and an interview.
"Mariah's Challenge stands for integrity, character and honesty and living a life of simple self-respect," said McCarthy, 52.
The message is something that is sorely needed in Butte, he said, one of a few places in the country where people can drink in public.
"Butte has an apathetic attitude in some ways to underage drinking," McCarthy said. "And it has a somewhat acceptance of drinking and driving. ... It's generational."
The city's drinking culture dates back to its history as a major mining town in the late 1800s, when it attracted boatloads of Europeans seeking better opportunities and a new life. Miners often went as deep as one mile underground to dig iron ore. It was tough work, and many of them often liked to drink at the end of the day.
"This town has such a hard history of living," McCarthy said. "It's a humbling town ... a town of integrity and character. But Butte allows certain things to continue, and drinking underage and drinking and driving is a situation that's continued. It has to be acknowledged, and it has to be stopped."
It's not just Butte, however, that is struggling with the problem. Nationwide, Montana routinely ranks in the top five per capita for drunken-driving fatalities. Those troublesome statistics, along with Mariah's story and other high-profile deaths, have led legislators to seek more aggressive ways to address the issue.
One example is the 24/7 Sobriety Program, which has been implemented in 16 counties, including Butte's, since last year. It requires anyone arrested for a second drunken-driving charge to submit to two alcohol breath tests daily.
"Montana finally has had enough," said Steve Bullock, the state's attorney general. "Tired of opening the newspaper, reading about somebody getting their sixth or seventh DUI. Tired of community losses. We're addressing it both through law enforcement, through legislation and through awareness.
"One of the great things about Mariah's Challenge is changing people's behavior and the positive awareness of it."
Courtney Cashell, a recent scholarship recipient, says she has noticed the culture starting to change in Butte.
"People are coming up with alternatives," she said. "I know of a group of kids that got everyone together and said, 'Just bring soda. We're going to have pizza and music. Don't bring any alcohol.' ... It's changing gradually, in little steps."
Josh Panasuk, one of 42 students to receive a scholarship this year, said Mariah's story inspired him to do something with his life other than just drink and party it up. He works two jobs, plays sports and plans to attend Montana State University Billings this fall.
"I kind of looked around and saw a lot of people I knew -- a lot of friends, for that matter -- just going down that path, and I never wanted to," he said. "It never appealed to me."
Mariah's Challenge started in Butte, but it has expanded over the years to other parts of Montana as well as four other states: Washington, Idaho, Iowa and North Carolina.
About 8,000 young people have accepted the challenge. But they're not the only ones.
"I have parents taking Mariah's Challenge. I have grandmothers taking Mariah's Challenge, not because they have a drinking problem or anything else like that, but they understand what it's about," McCarthy said. "They have the opportunity and the sage advice of looking back to people and looking at their future and their grandkids and saying, 'Hey, I'm the first one to acknowledge I've done some goofy stuff. But you know what, Mariah's Challenge is a great way for you to enjoy life ... to be something, to be somebody unique.' "
For him, seeing kids make responsible choices means Mariah's memory will live on.
"Mariah is forever 14," McCarthy said. "I can't get her back, but I can help other parents keep their kids safe.
"We save one child, we save a generation, and that makes me encouraged to continue what we're doing every day."
Want to get involved? Check out the Mariah's Challenge website at www.mariahschallenge.com and see how to help.