3700 4th St SW.
North Iowa Events Center, 3700 4th St Sw., Mason City (515-689-4654). Karts, Bikes, Quads and more will be back lighting up your North Iowa Fairgrounds. Races on Saturday begin at 1:00pm. Admission: $10 adult; $5 children 6-12; Free 5 & under. Pit passes: $20. https://www.facebook.com/ADayofThunder/