People from all over the country will be in Bismarck to compete in the the Kroll's Diner Bismarck Marathon.
The event kicks off at 7:30 a.m on Saturday and includes a marathon, half marathon, marathon relay, 10K and 5K run and walk.
Drivers should be alert for runners crossing streets.
Police and volunteers will be stopping traffic at times to let runners cross safely.
The marathon planning committee says drivers should be alert around the Expressway Bridge into Mandan and the Memorial Bridge in Bismarck.