1917 - GRUNDY COUNTY FAIRGROUNDS
The first motor racing on the 1/2 mile Grundy County Fairground was recorded in 1917, Midgets were the main attraction with the ability to fill the spectotor stands.
1935 - MAZON SPEED BOWL
In 1935 the speedway was reduced in size to a 1/5th mile to improve the spectacle of the racing, while still retaining its dirt surface, Like all other motorsport tracks, World War 2 would see Mazon Speedway close in 1941.
1946 - MAZON SPEED BOWL
In 1946 the speedway did re-open again but as a 1/4 mile dirt track, but not for long, as in around 1947 the tracks surface was paved and Stock Car racing dominated the calander.
1970 - MAZON SPEED BOWL
The track closed in 1970 for the final time, While speedway racing was moved to the Grundy County Speedway in Morris not far away.