Thirty-nine runners will brave the hilly streets of Seattle to support their cause.

The group – comprising of mostly Yukoners and some British Columbians – will run in the Seattle Rock ‘n' Roll Marathon and Half Marathon on June 25.

Team Ross and Finn have been taking pledges to raise money toward advanced research for Duchenne Muscular Dystrophy (DMD) – the disease affecting brothers

Ross and Finn Beaulieu of Whitehorse – through the U.S.-based organization called Parent Project Muscular Dystrophy.

The group met most recently on Thursday to do their weekly run up Schwatka Lake Road to prepare for the marathon and half marathon.

To date, Team Ross and Finn runners have raised $38,000, just below their goal of $40,000.

Michelle Beaulieu, mother of the two boys, said the team will likely surpass that goal before Seattle.

"Each runner had to commit to raising $1,000 and has to pay their own way down to do the run,” said Michelle, who teaches at Golden Horn Elementary School.

"It's been great to have so many friends of ours agree to do it, because it's a lot to ask people to commit to raising money and to train and to put up their own money to get down to Seattle and do the race.

"We thought maybe we'd get 20 people, if we were lucky, and we ended up with almost 40 runners, so that was pretty exciting, and then once people start fund-raising, it's just exponential, because everyone's got their own network of people that will pledge.”

Runner Robin Fairburn, who was Finn's Kindergarten teacher, said the community has pulled together around the Beaulieu family.

"It was so easy to raise once people know the Beaulieu's story. A lot of people in town have seen the boys. It's not just the people going to Seattle for the run, but I think our whole community is really pulling for Finn and Ross and the Beaulieu family.”

Pledges have been coming through the Run For Our Sons website, on which visitors can see how much each runner has raised and read their stories.

Sixteen-year-old Dawson Beaulieu, older brother to Ross, 15, and Finn, 11, said raising money is more important than finishing the half marathon in record time.

"The more important part is raising the money; it doesn't really matter what time I get on the marathon. My goal, instead of being super good at running, is to raise as much money as I can,” Dawson said, adding that his initial goal has changed because he's already raised more than $1,000.

"I think it's a great way to raise money. We have almost $40,000, which is crazy.”

Eight years ago the Ross and Finn were diagnosed with DMD, a fatal genetic disorder.

The result is progressive muscle weakness that leads to serious medical problems, particularly issues relating to the heart and lungs.