Billings Schools Superintendent Greg Upham announced Saturday he will require masks for all students, teachers, visitors and other employees during the normal school day to start the school year.
Upham cited a COVID-19 outbreak among students on a Billings Skyview fall sports team as the impetus to reverse his decision just two days ago to keep masks optional.
In a letter addressed to school district stakeholders, Upham said the level of the outbreak was significant enough to cancel a scheduled game.
Upham told MTN News in an interview that the outbreak occurred on Billings Skyview's varsity football team and forced a cancellation of a junior varsity football game.
Three positive COVID-19 cases were reported on the team Wednesday, then two more on Thursday, then one more on Friday, Upham told MTN. Two more students were quarantined as a precaution, he said.
Upham added that what started as one positive case spread enough to infect 10 percent of the team.
"If this same rate of transmission occurred in our classrooms during the first week of school, we could potentially have hundreds, if not thousands, of our students out of class within a short time frame if we do not mask. School districts in other states have already seen that occur," Upham wrote.
The mask mandate goes into effect Sunday. Classes are scheduled to start Monday.
Upham said he would monitor the COVID situation in the area "weekly" to determine how long the mandate should stay in place.
Upham also cited rising COVID-19 infections in Yellowstone County, including among young people, shrinking hospital capacity and the "highly infectious" Delta variant as reasons supporting his decision.
On Thursday morning, Upham announced that masks would be optional at school for students. That decision came a day after the district's teachers union rejected his request to require masks in all K-8 buildings.
According to Billings Education Association President Doug Robison, members of teachers and classified staff unions said they did not want to amend an agreement they signed this summer with the district making masks optional for staff.
Upham told MTN that the district's attorney believe the masking policy supersedes the agreement signed by the unions, and he has informed union leaders.
Upham added that he has also informed all district trustees of the policy change, and all are in support.
Q2 News has reached out to a union representative and will update this story with any comment.