Picket lines formed around 9 am Wednesday morning outside of Line Mountain Elementary School in Trevorton
Wednesday was the first day of the strike.
The district and education association remain at odds over issues such as salary and class size.
Officials announced that after school activities would not be affected by the strike.
The teachers have been working without a contract for three years.
The next regular meeting of the Line Mountain School board will be held on Tuesday, September 22nd at 6:30pm in the high school library.
This is the second district to strike in Northumberland County this year.
Shamokin Area is also on strike.