Boise, Kuna and and Skyview High schools in Nampa were targets of the bomb threats. Police in Caldwell said someone called the school threatening to "start shooting people at the school."
Bomb threats were made at Kuna and Boise High at exactly 10:50 a.m. The Skyview call came in at about 11:45 a.m., Nampa Police tells KBOI-TV while the threat at Caldwell High came in a few minutes later.
At Boise High, students at first thought it was just a fire drill when they evacuated.
"But then we found out it was a bomb threat," said junior Melanie Overstreet. "That was kind of scary. Never thought something like that would happen in Boise."
Melanie's father, Bob, works nearby and quickly showed up to check the situation out.
"I wasn't too worried," he said. "Everybody was out of the school. Everyone was safe. There was no fire or anything like that."
All of the high schools received the threatening calls were participating in ISAT examinations.
"We are aware that this is happening at schools around the valley and will coordinate with those other agencies in the investigation of this crime," Caldwell Police said.
Making bomb threats is a felony, chargeable to juveniles or adults, and punishable by up to five years incarceration.
"We want you and your student to know we take this matter very seriously," the Boise School District said in a message to parents. "A top priority has always been and continues to be the safety and security of our students and staff members."
Anyone with information about the threats is asked to call 343-COPS.