Aja Goare of KTVQ reports the Dawson County Health Department is investigating an outbreak of E. coli at the Richey Centennial that sickened more than 30 people.
The event took place the third weekend in July in Richey, which is about 50 miles north of Glendive.
Health officials do not know exactly where the outbreak originated, but they believe it may have originated with a local food vendor present at the event.
According to the DCHD, the vendors have been cooperating with the investigation.
People who attended the event are discouraged from consuming any leftover food they may have from the event and are asked to turn it over to the local health department.
At least six of the people who became ill have been hospitalized.
Visitors from eight different states and six Montana counties have become ill, according to the DCHD.
New cases are still being reported and additional laboratory results are pending.
On a Facebook page created for the event, a Nevada woman who attended reported that her mother had been hospitalized for several days due to the illness.