NORTHAMPTON — The second annual Runway 5K to support the Easthampton nonprofit organization Treehouse will occur Sunday, after the group turned a scheduling mishap into a positive partnership opportunity.

Treehouse officials originally scheduled the race, which features around 300 participants running on the tarmac of the Northampton Airport, for a Sunday in mid-May. But the event had to be rescheduled due to the airport’s owners, Bob and Andrea Bacon, having to attend their child’s graduation ceremony on the original date.

The nonprofit that supports children who have experienced the foster care system then scheduled the 5K event for April 28 — only to realize less than two months before the race that it fell on the same day as another planned 5K to be held on that day: the Big Brothers Big Sisters of Hampshire County’s Daffodil Run in Amherst, supporting that organization’s one-to-one youth mentoring program, connecting adult mentors with younger people, helping them to build relationships.

After realizing the mishap, Treehouse contacted Big Brothers Big Sisters to try to come up with a solution. The latter organization agreed to move their event to one week later, and in turn Treehouse would have a table to support Big Brothers Big Sisters at its race this Sunday.

“That was above and beyond. They didn’t have to do that,” said Jenneke Reynolds, a volunteer for Treehouse who serves on the committee that organizes the 5K. “It’s not surprising since they’re both nice organizations, but it’s just so great when things go so well like that.”

It will be just the second time Treehouse hosts the 5K, after debuting the event last year. In addition to the race, the event also features craft tables for kids, decorating the airport’s hangar and weather permitting, displaying several vintage planes to add to the flair of the 5K, such as a World War II-era Waco airplane.

Last year the event raised more than $80,000 for Treehouse, beating the nonprofit’s expectations. Reynolds said this year they are aiming to bring in more than $100,000.

“Right now we’re close to 80% of that goal,” Reynolds said. “It’s definitely reasonable for us to get there.”

The Runway 5K race begins at 9 a.m., with runners and walkers traversing the length of the runway, before turning and looping back around to complete the race. Though registration to participate is sold out, people may still sign up to sponsor a runner and donate to Treehouse. Prizes go to the individuals and teams who raise the most in donations, the first to cross the finish line in age categories, and the most enthusiastic walkers.

Meanwhile, the 14th annual Daffodil Run will be held at the Amherst Town Common at 10 a.m. on May 5, followed by a post-race party. To register, visit racewire.com/register.php?id=14021

Alexander MacDougall can be reached at amacdougall@gazettenet.com.