The news was first announced Friday by the National Park Service, which manages the Santa Monica Mountains National Recreation Area.
We are sorry to share the news that the #WoolseyFire has burned Western Town at #ParamountRanch in Agoura. We do not have any details or photos, but it is our understanding that the structures have burned. This area is an active part of the incident and we cannot access it. pic.twitter.com/oC4n7KR8ZT
The church featured in the HBO series was also built on the ranch and appears to be still standing, according to a tweet from cast member Evan Rachel Wood, who plays the sentient android Dolores Abernathy.
It is not yet clear how the fire will affect production of the show.
"Paramount Ranch was one of the locations used during seasons one and two of Westworld, in addition to the primary location at Melody Ranch in Santa Clarita," Quentin Schaffer, an HBO spokesperson, said in a statement sent to Ars.
"Westworld is not currently in production, and as the area has been evacuated, we do not yet know the extent of the damage to any structures remaining there. Most importantly, our thoughts go out to all those affected by these horrible fires."
Paramount Ranch was also used in the production of numerous movies and TV shows going back decades, including Dr. Quinn, Medicine Woman.