Polson resident Mervin Payne said the West Garceau fire, burning five miles west of town, was hard not to notice Tuesday because of all the smoke.
He said he drove by the fire on the way to lunch, and when he drove by an hour later, he was shocked by how much it had grown.
"It had already moved a mile towards the south, which really surprised me that it would burn so quickly," Payne said.
The blaze started Monday afternoon, and wind pushed the fire to over 8,000 acres by Wednesday morning.
On Wednesday evening, fire officials said crews battling the fire were able to successfully utilize retardant drops during the day along the fire perimeter, and they estimate 5% containment.
Public Information Officer Jennifer Costich said late night and early morning rained slowed the spread.
"The rain that occurred last evening was a good temporary reprieve for us,” said Costich. “It should give the firefighters some opportunity to get a good fire line established."
The fire is burning primarily on tribal land. It forced three families to evacuate their homes Tuesday, but officials allowed them to return the next morning.
The official cause is undetermined, but tribal officials said Tuesday that investigators suspect the fire was human caused.
Officials set up a Type II Incident Management team at the Polson fairgrounds Wednesday to coordinate the containment effort. 122 people are currently fighting the blaze.