“A school in Grass Valley is closed Thursday over a teacher shortage, school officials said. Nevada Union High School posted the announcement on the school’s home page. In a letter to families, Kelly Rhoden, the school’s principal, said: ‘It is our top priority to get students back in the classroom to further their education as soon as possible. We will be working closely with the teachers union and the district administration to find a quick resolution to our current situation. We apologize for the inconvenience and thank you for your patience and support as we work through these challenges.'”
Jeff Pelline's Sierra Foothills Report 
Open letter from NJUHS teachers association: https://yubanet.com/regional/open-letter-from-nevada-joint-union-high-school-teachers-association/