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Photo: On March 27, 2019 a press conference was held on the Tres Hermanos Ranch property recognizing the new Tres Hermanos Conservation Authority. Representatives from each of the three cities were in attendance.

The Tres Hermanos Conservation Authority (Authority) is a joint powers agency with representatives from the cities of Chino Hills, Diamond Bar, and Industry. The purpose of the Authority is to coordinate the overall ownership, maintenance and use of the 2,445-acre Tres Hermanos Ranch property through the collaborative efforts of its Member Agencies.


Tres Hermanos Ranch is 2,445 acres of undeveloped open space located along the eastern edge of the city between Diamond Bar and Chino Hills.


Tres Hermanos Ranch is owned by the Tres Hermanos Conservation Authority, a joint powers authority with the cities of Chino Hills, Diamond Bar and Industry.  The City of Industry transferred to property to the Authority on February 11, 2019 as part of the settlement agreement between the three cities.


Reconstituted Tres Hermanos Conservation Authority - 

This agreement between the Cities of Diamond Bar, Chino Hills and Industry brings to a close a 15-month legal battle that involved litigation challenging the sale of the Tres Hermanos Ranch from the Industry Successor Agency to the City of Industry and the Master Lease which contemplated the construction of a large solar generating facility on the 2,450 acres of undeveloped open space located between Diamond Bar and Chino Hills.

Three things are achieved with this agreement – (1) it resolves six pending lawsuits filed by the Cities of Diamond Bar and Chino Hills against Industry, (2) it amends the existing Tres Hermanos Conservation Authority Joint Powers Agreement (JPA) to create a newly re-constituted Tres Hermanos Conservation Authority, and (3) it paves the way for the purchase and sale agreement that transfers the Tres Hermanos Ranch from the City of Industry to the Conservation Authority. The purchase and sale agreement to transfer the Tres Hermanos Ranch to the Conservation Authority will limit the use of the property to “open space, public use or preservation”.

Under the amended JPA, this new Conservation Authority will have a seven-member governing board with seats filled by two Diamond Bar Council Members, two Chino Hills Council Members, and three Industry Council Members.