With three weeks to go, the number of runners set to take part in the Kroll's Diner N.D. Roughrider Marathon has tripled from 2006 and nearly doubles last year's figures.

A full marathon, half marathon and marathon relay (teams of five) will start at 7:30 a.m. Saturday, Sept. 20.

As of Friday, 160 runners had signed up for the full marathon and 310 for the half marathon. Last year there were 199 participants in the half marathon: "That's where we have the biggest growth,"said David Nash, marathon committee chairman.

The marathon relay registration was closed three weeks ago, with nearly 300 runners set to take part.

When full marathon runners pass the relay points, they get a boost of energy from all the people cheering, said Marnie Walth, a marathon runner and a member of the organizing committee.

The increased number of runners means a need for as many as 200 volunteers, said Julie Bosch, who, with Bryan Wetch, is co-chair of the volunteer committee.

"We need course monitors and help with parking," said Bosch, who estimates 150 volunteers have already signed up.

Because of the open road and the number of runners, Nash said, "we couldn't do it without the volunteers."

And, Bosch said, there's a need for entertainers, who work the marathon route. "When you run that distance, it's a nice diversion," she said. People wanting to entertain along the way should contact Bosch.

Runners will vote for their favorite water stop and entertainment. There are cash prizes to be won, Bosch said.

Nash said, "People at the water stops are not just giving water, they are cheering you on." Nine water stops are planned.

The start and finish will be at Pioneer Park. Parking for runners and spectators will be at the Community Bowl, with a bus shuttling people back and forth.

The general route of the marathon will be south from Pioneer Park on Riverside Park Road, east on Burlington Avenue, south on Washington street, east on 48th Avenue South and south to a turnaround point on Sibley Drive and then back again.

"We encourage the community to turn out and support the race," Bosch said.