Governor Bullock announced that his July 15 directive requiring masks in counties with four or more active cases is now immediately applicable to public and private schools.  In short, this means face coverings are required for school districts in counties with four or more active cases. See the attached directive.
A key excerpt from the Governor's Directive:

Therefore, in accordance with the authority vested in me under the Constitution, Article VI, Sections 4 and 13, and the laws of the State of Montana, Title 10, Chapter 3 and Title 50, Chapter 1, MCA, and other applicable provisions of the Constitution and Montana law, I hereby direct the following measures be in place in the State of Montana, effective immediately: 

1. The July 15 Directive providing for the mandatory use of face coverings in certain settings is hereby amended to require the use of face coverings, as detailed in that directive, in all public and private K-12 schools in counties with four or more active cases. 
2. All provisions set forth in the July 15 Directive apply to public and private K-12 schools. 
3. Indoor school spaces are considered indoor spaces open to the public.
4. School-related outdoor activities are considered organized outdoor activities.
5. All provisions of the July 15 Directive remain in effect except as expressly amended by this Directive. 

Cascade Public Schools will adjust it's reopening plans to meet this mandate.

If you have concerns about this requirement please contact the Governor's office at 855-318-1330 or 406-444-3111.  You can reach his office at this link: http://governor.mt.gov/Home/Contact/shareopinion and on Facebook: https://www.facebook.com/GovernorBullock/