Kevin Conwell, principal of Bozeman High School, said the bear was first spotted on the football field about 7:30 a.m. Wednesday and the animal soon found its way into the building through an open garage door in the custodial area.
Conwell said students snapped photos and captured video of the bear, but they remained at a safe distance from the animal at all times.
"They were being careful. They were keeping a good, safe distance," Conwell told the Bozeman Daily Chronicle.
The bear eventually left through an open exit and police helped guide it back to a more hospitable area.