A harsh winter and the promise of more severe weather led to the cancellation of the Martha’s Vineyard 20-Miler Road Race, which was scheduled for Saturday. Race organizers and emergency personnel said there were concerns about runner and volunteer safety on the icy, narrow course, some of which is still buried under snow.

This is the first time in the event’s 18-year history that it has been cancelled. The 20-Miler is a primary fundraiser for the Martha’s Vineyard Boys & Girls Club and a contributor to several other Island nonprofits. The race attracts competitive runners from all over the country, including members of the Boston Athletic Association, and is organized by a large group of Vineyard volunteers.

“Every year, about 70 to 80 per cent are returning runners,” Boys & Girls Club executive director Peter Lambos said on Wednesday. This year, there were 403 individual runners and 70 two-person relay teams registered to run. As part of the race registration policy, the $40 race fee is nonrefundable. A portion of the fee goes towards race expenses such as police details, food, prizes, and T-shirts, while the remainder goes towards the nonprofit organizations involved. The race does not have financial sponsors.

The decision to cancel was made Monday after Mr. Lambos met with Island emergency management, police, and fire departments. Runners were notified by email shortly after. Those registered for this year’s race will receive a 25 per cent discount on next year’s event; their race T-shirts will be mailed to them.. Mr. Lambos said that most racers were disappointed, but understood the decision.

The race will not be rescheduled due to the lengthy permitting process for the course (Mr. Lambos began preparing for this year’s race last August). There was also concern about creating conflicts with other local road races that take place in the spring.

Although the race has been run before in less than ideal weather—last year, it started to snow halfway through the event—existing slippery conditions were expected to worsen over the weekend, with temperatures in the teens and single digits. Part of the course goes through the state forest, and paths there are still coated in ice. To maximize runner safety, the race takes place primarily on bike paths, but many of these are buried under snow, which would force runners to be in the road.

“It was just apparent that with the cold temperatures nothing was going to be able to be plowed out,” Mr. Lambos said.

He was also concerned about the safety of volunteers, many of whom are elementary school students and teens from the other nonprofits that participate. This year’s partner organizations included Friends of Vineyard Soccer, the YMCA, the MV Touchdown Club, and Martha’s Vineyard Figure Skating.

“I can’t have a group of 12- and 13-year-olds standing on the white line of West Tisbury Road just to hand out water,” Mr. Lambos said. “The volunteers would still have to be out, and there was no safe place for them.”

“It’s tough, but we'll live with it,” he said.