>>3848115
It's partly terrain. The wild places with timber in the Sierras and coastal range are mountainous, steep, and inaccessible. During wildfires they use aircraft as well as hand crews (when the hand crews can even access the place). The aircraft are necessary IMO. There's a pilot craft that leads the other aircraft in, various tankers that drop retardant to create temporary fire lines so the bulldozers can cut lines, water tankers, helicopters that pick up loads of water from reservoirs and lakes, and drop the water from their aerial buckets, etc. I'm acquainted with several people who are or have been CA firefighters, and have observed (via web + radio) numerous of these wildfire fighting efforts. After the fire is finally surrounded and contained, they are required to perform remedial work to rehabilitate drainage areas to prevent rock and mudslides, take down dangerous trees that might fall and kill someone or block a road, restore natural contours, etc. I think planting of tree seedlings also occurs after a fire IIRC.
Link to CalFIRE aviation resources brochures:
http://www.calfire.ca.gov/fire_protection/fire_protection_air_program
I do know that professional firefighters "hope" for continued regular work, to justify their budget and job. This is disturbing but I heard it from an environmentally conscious, right-wing, cattleman who one presumes does not actually hope for terrible fires to occur. It's a strange disconnect.