Reese Public Schools said there was no credible threat after the district went into shelter in place.
Reese Middle/High School went into shelter in place at around 9:05 after Reese Police said a bomb threat was found written inside a bathroom stall.
The district said local authorities arrived, and the shelter in place was lifted at around 11:55 a.m.
Police said they do have a person of interest in mind, but no one is in custody.
Law enforcement is investigating.