UPDATE: The forward spread of the fire was stopped at 11:30 a.m., according to Cal Fire.
The threat warning to the structure has been mitigated.
The fire grew to 7 to 10 acres.
Cal Fire and local fire protection districts were fighting against a vegetation fire growing moderately in Sheep Ranch late this morning.
The fire was growing slowly at 10:28 a.m. after being reported at 9:54 a.m., according to Lisa Williams, Cal Fire spokeswoman.
One structure was threatened around Armstrong and Hubbard roads.
It was estimated to have burned 3 acres.
No other details were available.