Assembled parcel by parcel since September 1978, Skywalker Ranch has cost Lucas up to US$100 million, according to the Wall Street Journal. After neighboring ranchers complained that Skywalker Ranch was polluting the environment, Lucasfilm acquired 3,000 acres (12 km²) of adjoining land for a total of over 4,700 acres (19 km²). Only 15 acres (60,000 m²) have been developed.