Maybe the USAF can spare some of those big tanker sized transport planes. I've heard for years that the US Forestry Service fleet is nothing but a bunch of broken down and unreliable WWII surplus planes. Sans rain with 100+ degree temps that is really the only way to try to control this. It's too hot to try to manage it from the ground.
The C-130s that you are seeing are military - there are no civilian C-130 air tankers. The military ships are fitted with removable tank systems - MAFFS - and there are a limited number of those. MAFFS are less effective than dedicated gated retardant ships, but they're better than nothing.
This year there are only 7 large air tankers on contract to the US gov't. There were 9 but two crashed. MAFFS, Canadian Convairs on loan, single engine air tankers, and helicopters are trying to take up the slack, but decreased funding from Congress and inertia on the part of the fed agencies has led to the current woeful state of the large air tanker fleet in the US.
The DC10 tanker has been activated on a call-when-needed basis by the feds but the drop height it requires and it's lack of maneuverability make using it problematic (and occasionally useless) in high winds and tight terrain.