Update 2:30 p.m. March 20: The search of Frenchtown high school and middle school has turned up no evidence of a bomb according to officials.

A bomb-sniffing dog and trained investigators were unable to find any sort of explosive device in the school.

School personnel were back in the building at 2:00 and, according to the Frenchtown school website, school will go on at it's regularly scheduled time tomorrow.

According to Sheriff's Deputy Paige Pavalone, the bomb threat was not a letter, but was actually a message scrawled with green highlighter on a boy's bathroom mirror.

Original: As of 11:00 a.m., March 20, Frenchtown middle school and high school were being evacuated because of a bomb threat.

According to Missoula County Sheriff's Department spokeswoman Paige Pavalone, a note was found in the boy's bathroom of the junior high that threatened that "there would be a bomb in the school today."  The note was reportedly written with poor grammar.

Students with cars have to leave and return home. Students without cars are being bused to Frenchtown elementary school. All personnel are leaving the facility, and because of the size of the complex, the building will be closed throughout the day for a full investigation