Okay so, struggling to find any aircraft dispatch sites, strange, Aus you can see all aircraft and where they are working.
Anyway, there is the following complexes that fit that area you mention:
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Greeg Mountain - [38.495, -122.35043] - (this is a big fecker, 363k acres, so would have had heavy metal on it).
LNU Lightning Complex (includes Hennessey, Gamble, 15-10, Spanish, Markley, 13-4, 11-16, Walbridge)
Terrain for this one looks like it could one to look closer at, just off Napa Valley. Very possible location.
Couple of small ones south west of there near Pentaluma. Small however and wouldn't expect there to have been much heavy iron on those, likely just mediums and light fixed wing.
-Quail Fire - [38.470809, -122.038208]. Possible deliberately lit fire, close to road access and got going, but not huge, wouldn't have expected any aircraft of much size there and ridelines dont really match the image.
Not looking into Mendocino, too much folliage on the terrain there to match the image. Napa area looks a good place to start.
https://www.fire.ca.gov/incidents/2020/