The People's Center in Pablo that caught fire Sunday night, killing the man suspected of starting the blaze.
CSKT Tribal Council member Martin Charlo told MTN News the real loss isn't the building itself, but all the history that was inside.
"It feels like it's a death in our community," he said. "A lot of priceless artifacts that have been either passed down for generations or found."
Charlo added that historical documents were all lost in the fire.
"That's going to be the major impact...that a piece of our history has been kind of burned," Charlo said.
Julian Michael Draper, 33, of Pablo was found dead on the floor, behind barricaded doors.
Lake County Sheriff Don Bell says he is a suspect in the fire -- and was arrested late last month for arson.
"I don't feel it was done out of hate, I don't feel it was done against our Tribe or our people," Charlo said.
"I just want people to know in this divisive time, this was not an act of vandalism or anything," he added.
Charlo says his hopes and prayers go out to the family.
"Very somber. Tears being shed. It's really sad. Like I said, it feels like a part of our community died today," he observed.
"We're a resilient people, and we'll get through this, but it's going to take some time," Charlo continued.
He says that due to the time of the year they probably won't be able to start rebuilding until next spring.
Charlo added that while the gift shop was also a complete loss, they hope parts of the museum will be salvageable.
Draper's body has been taken to the State Crime Lab in Missoula for an autopsy.
Fire crews remained on the scene until 7 a.m. on Monday watching for hot spots.