Big Sky Movie Ranch is a movie ranch located in Simi Valley, California, that has been used for the filming of Western television and film productions. The ranch is within the Los Angeles Studio Zone. The site is part of the 12,500 acres (5,058.57 ha) purchased by the Patterson Ranch Co. in 1903 to raise grain, cattle, hogs and sheep. The Ventura County Cultural Heritage Board designated several of these buildings County Landmark #71 in July 1981. Many of the sets were destroyed by a wildfire in 2003.[2][3]