We just witnessed some sanctioned hillside burning while driving through wine country.
During the dry season, the California forest department deliberately sets fire to parts of the hillside so that wildfires do not spread uncontrollably. People are hanging out by the side of the road watching the blaze.
Note: As we continue driving, law enforcement vehicles are whirring by us sirens blaring and lights flashing, so maybe this burn is not as "controlled" as it first appeared.
Note 2: Okay. Apparently, we just witnessed a natural fire, because it seems like every state vehicle in the area is rushing to the scene. The spectators we saw must have been idiot tourists like us, and/or locals keeping an eye on things until law enforcement arrived.