The history is deep... 

From the Santa Monica Mountains Conservancy website: 

Welcome to King Gillette Ranch, home to some of California’s newest preserved and protected open space. This beautiful parkland has been a haven to people, plants and animals for thousands of years.

History
The human history of this space begins with the Chumash, who lived in the areas for at least 9000 years; their village of Talopop is thought to be located nearby. In 1776, José Bartolome Tapia journeyed through the areas with the de Anza Expedition.

Razor baron King Camp Gillette bought the property in 1926. Gillette commissioned leading Los Angeles architect Wallace Neff to build him a "paradise on earth, California style." MGM movie director Clarence Brown (Anna Karenina, National Velvet) bought the property in 1930, following Gillette's death. Brown built a private airstrip for elaborate MGM "fly-in parties" that were attended by such luminaries as Clark Gable and Greta Garbo. In 1952, the director sold the ranch to the Claretian Order of the Catholic Church. In 1978 the site was purchased by Elizabeth Clare Prophet's the Church Universal and Triumphant, which in turn sold it to Soka University of America in 1986.

In April 2005, the site became a haven for all living things in perpetuity, when it was bought as public parkland by a partnership consisting of the Santa Monica Mountains Conservancy, the Mountains Recreation and Conservation Authority (MRCA), the National Park Service, California State Parks, as well as a number of other state and local agencies and some private contributions. King Gillette Ranch opened to the public in June of 2007.

King Gillette Ranch supports a wide variety of wildlife, including eight “sensitive” species that inhabit the property. It is also home to several sensitive plant communities and many large specimens of Valley Oak.