A teacher strike began Thursday morning in Medford after all-night bargaining.
KDRV-TV (http://bit.ly/1iuTTMD ) showed picketers in front of the school district offices after a 6 a.m. deadline set by the teachers union passed.
Superintendent Phil Long told the station the two sides "ran out of time."
The president of the Medford Education Association, Cheryl Lashley, said talks would resume Saturday.
The school district has cancelled classes through Monday in the event of a strike and plans to reopen Tuesday with substitute teachers and security guards.
School days will be shortened to four hours, students from smaller schools will be moved to larger buildings, and extracurricular activities except for high school sports are to be canceled.
The two sides said they disagreed on pay, health insurance, workloads and early retirement incentives.