CHEYENNE, Wyo. — Sarah Keefe has always enjoyed riding her bicycle around the neighborhood, but this summer her hobby has taken on a new purpose: fighting cancer.

The 14-year-old incoming freshman at South High School is pledging to ride her bike at least 100 miles this September to raise money through the Great Cycle ChallengeUSA. Sarah’s goal is to raise $2,500, and so far she’s raised $1,589. No matter how much she ends up raising, all of the proceeds will go to the Children’s Cancer Research Fund.

The cycling fundraising initiative launched in 2015. According to the organization’s website, cyclists from all over the country have ridden a total of 18,831,310 miles and raised $24,615,507 “in support of research to develop better treatments and find a cure for childhood cancer.”

Although Sarah has not personally experienced childhood cancer, the mission of the bicycle challenge is still deeply personal. Earlier this summer, Keefe’s uncle, Alvin Keefe III, died in his early 40s after a cancer diagnosis, the Wyoming Tribune Eagle reported.

“It was really upsetting that we couldn’t have longer together,” said Sarah, wearing a white cycling jersey with the Children’s Cancer Research Fund logo printed on the chest.

“I feel like this is a way I could help kids be more like me,” said Sarah, who plays for a traveling basketball team when she’s not riding her bike. “I love nature. I love the wind. I feel so sad for kids with cancer who can’t enjoy the outdoors like I can.”

Right around the time of Alvin’s passing, Sarah and her mother, Tasha, heard about a friend in Michigan who was raising money for cancer research through the cycle challenge.

“That’s where she got the motivation to do it,” said Tasha, who praised her daughter’s drive to succeed in sports, academics and community service. “She’s always doing something. She gets straight-As, she’s in honors classes. She’s outgoing and friendly. It was no surprise that she wanted to d

The challenge doesn’t officially start until Sept. 1, but Sarah has already logged about 20 miles, and she hit her original fundraising goal of $1,000 weeks ago. To date, she has raised the most money of all Wyoming-based participants and is the 307th highest earner in the nation.

Perhaps the hardest part for Sarah will be finding a good long route to log the 100 miles she’s told her sponsors she’ll ride. Right now, she’s been circling the neighborhood streets surrounding her family home in south Cheyenne, but is looking into more extensive routes.

Even after the challenge ends, though, Sarah said she has her sights set on a career in health care, and specifically occupational therapy.

“I’ve seen my brother, who has a learning disability, work with occupational therapists at school, and it’s been really helpful,” she said. “If there’s kids at the hospital who might have cancer, I want to help them get better and be able to enjoy life like I do.”