The state and federal agencies are only supposed to fight wildfires on their lands and adjoining lands, if the fire spreads. Of course if they come upon a house in danger, they will do what they can (being good neighbors).
In the paper today the stories on the Corral Fire (outsdie of Helena) included the sheriff telling some people to evacuate (which they were supposed to do two days ago) and while he was warning them the wind shifted and the fire was heading straight for them. The sheriff got the hell out of Dodge, being a man of great common sense. The people did too.