On September 30, 2003, Washington Mutual reached an agreement in favor of halting development and selling the Ahmanson Ranch property, due to lengthy and costly litigation and the continuing pubic controversy about the project’s impacts on the environment. 

The park is now open to the public for visiting and hiking, and has been re-named the Upper Las Virgenes Canyon Open Space Preserve. 

The ten year fight against the development, begun by Mary Wiesbrock and other local activists, culminated in the $150 million deal funded by the state to buy Ahmanson Ranch from Washington Mutual and make it part of the Santa Monica Mountains Conservancy.

The state Wildlife Conservation panel allocated $135 million of state bond money. Making up the rest of the $150-million purchase price was the state Coastal Conservancy, which contributed $10 million, and the Santa Monica Mountains Conservancy, which contributed $5 million.

The Village of Huwam
Huwam is significant because, prior to European contact, this village was an area where Chumash, Tongva, and Tataviam people lived and interacted with one another. Some of the stories still passed down through oral tradition illustrate this point. For example, versions of the story of Munits appear in the oral histories of Chumash and Tongva people. It is possible that the stories associated with landmarks located on Ahmanson served to define political boundaries between the different nationalities that resided there.

Kas'elew (Castle Peak)
This site has traditionally been an area of great ceremonial importance for Chumash people. It was traditionally used by priests and astronomers during winter and summer solstice ceremonies.

This site is also significant because it is one of nine alignment points located within Chumash territory. These points are central to maintaining balance in the natural world.

Though Castle Peak is located on the LA County side and was therefore not a part of Ahmanson property, it is important to note that the Cave and the Peak can be seen from one another. This connection and proximity makes the cave and the peak a continuous area of significance that should not be broken up

Cave of Munits
The cave is important because stories about its significance are still known by Chumash people today. According to oral history, this cave was the home of a very powerful shaman who eventually met his end after murdering the son of a politically important chief.