The school sent out a notification around 9:45 a.m. Tuesday to say students and staff were being evacuated from the high school to the middle school.
Police, with K-9 units, conducted a search of the high school and determined it was safe to re-enter.
Investigators say the threat was reported by a student to the school administration.
Police tell Action News that student overheard the bomb threat from another student.
Police have interviewed the student who overheard the threat and are trying to identify the student who made the threat.