The all clear has been given at Boise High after bomb dogs completed their search.
Staff and students have been allowed back in.
They were all evacuated to the school's football field as a precaution when the threat was called in just before 11.
Some parents picked up their students at the school.
Kuna High and two schools in Canyon County also received threats today.
Boise PD says making a bomb is a felony even for juveniles. Anyone with any information is asked to contact CrimeStoppers at 343-COPS.