If the Lolo Creek Complex were to make a big jump, as many as 1,200 houses could be at risk.
The smoke on the hillsides of Lolo is from flames 4.5 miles away.
Being the nation's No. 1 priority fire is a mixed blessing.
"That has its advantages nationally," said fire information officer Dixie Dies, "because there are so many other fires going on. It gives us the edge up for the resources that we need, and we are getting the resources that we need."
Out on the line, one of the toughest challenges is the steep terrain.
"There's not a lot of good access," said Dies, "that's why we rely so much on retardant."
Aircraft have dropped hundreds of gallons of retardant and thousands of gallons of water. There are 9 helicopters.
In camp, NBC Montana met several firefighters from Browning. They were helping take care of the camp. They distribute the tons of gallons of water and ice. They hand out lunches, and if needed, will tackle flames too.
"This is my squadron," said Craig Daniels, "We're the Blackfeet Nation from Browning."
Firefighters are coming from all over Montana, and all over the country to fight the 9,500 acre blaze.