This Saturday, the 45th annual Chilmark Road Race will return to Middle Road, testing the will of 1,600 runners in a hilly, five-kilometer course.

“The spirit of the road race is both fun and competitive,” said Hugh Weisman, founder and director of the event. “A lot of people start out here, running it as a lark for the first race. And then, all of a sudden, they are competing.”

The course includes scenic views of rolling farmland, before hitting some heartbreak hills and concluding at the festive finish line at Beetlbung Corner by the Chilmark Town Hall. All runners must check in at the Chilmark Community Center Friday from 5 to 7 p.m. or Saturday morning from 8:30 to 9:30 a.m.

The race begins at 10:30 a.m.

While the course’s winding route is famously difficult, it remains an essential August tradition. According to Mr. Weisman, the race usually reaches capacity less than a week after registration opens.

For Mr. Weisman, the storied history of the race has officially made it an Island institution. He reminisced about generations of runners who have returned annually since the inaugural race in 1978.

“You have at least a few grandparents running it this year, after first running it when they were teenagers,” Mr. Weisman said. “It means a lot to people on this Island. People organize their vacations around it.”

The runners are broken down by age group, with the overall course record belonging to Art Smith, who set the record in 2012 with a time of 14 minutes and 38 seconds. The oldest record holder is 91-year-old Susan Wilson, with a time of 57 minutes and 42 seconds in the 90-plus division.

All profits from the race go to the Chilmark Community Center, specifically funding scholarships for Island kids to attend the center’s summer camp.

More information about the race is available at chilmarkcommunitycenter.org.