I think May 10th is the earliest the marathon has ever been run in Fargo. Not sure if that is keeping the numbers down. As of 4/28/15 there is plenty of room left in all races. In previous years that has not been the case.
Good that the weather has been warming up although all races start inside the Fargo Dome except the 5K.
A route change this year will keep the marathon north of 94 and include a considerable increase in mileage on the Moorhead side of the river. Looks like 4 miles in the middle of the marathon. The half does not even cross the river. And the 10K and 5K stay relatively close to Fargo Dome and Mickelson Field. Basically opens up more spectating locations in Moorhead in the neighboorhoods adjacent to Concordia College.