Center for Biological Diversity

For Immediate Release, January 11, 2018

Contact:  J.P. Rose, Center for Biological Diversity, (408) 497-7675,
Pam Nelson, Sierra Club, (951) 767-2324,
Lynn Cullens, Mountain Lion Foundation, (916) 606-1610,
Vicki Long, Cougar Connection, (951) 698-9366,

Lawsuit Challenges Development That Could Doom California's Santa Ana Mountain Lions

TEMECULA, Calif.— Conservation organizations sued the city of Temecula today for approving the Altair housing development, which would endanger the local mountain lion population by disrupting critical wildlife corridors. The groups include the Center for Biological Diversity, Sierra Club, Mountain Lion Foundation and Cougar Connection.

Today’s suit, filed in Riverside County Superior Court, notes that the Altair project would urbanize approximately 200 acres of open space for a mixed-use development and a multi-lane highway in the hills above Old Town Temecula. Part of the development sits on the 55-acre “South Parcel” — the only passage left for wildlife to move between coastal and inland mountains through the Santa Margarita River, Temecula Creek and the Santa Margarita Ecological Reserve, which are adjacent to the project.

“The city council’s Altair approval ignored scientists’ warnings that developing the South Parcel will severely limit mountain lion movement in Southern California,” said J.P. Rose, an attorney at the Center for Biological Diversity. “It’s deeply disturbing that the city refused to make reasonable modifications to the development to avoid damaging a critical corridor for these iconic predators.”

As few as 20 adult Santa Ana mountain lions survive, and they suffer from severe genetic restriction because overdevelopment already curtails their movements.

“The project’s poor design will put mountain lions directly into residential areas, creating conflicts between lions and people,” said Lynn Cullens of the Mountain Lion Foundation. “These lions already suffer from high mortality rates, vehicle collisions, and a lack of genetic diversity due to urban sprawl and highways. Altair could be the final nail in the coffin for this crucial population of magnificent animals.”

“Scientists have documented consistent use of the South Parcel by mountain lions,” said Vicki Long of Cougar Connection. “The city should be strengthening this critical corridor instead of literally putting up barriers to mountain lion movement.”

Altair also does not do its part to reduce greenhouse gas emissions that fuel climate change. “Even though the city has a duty to reduce the greenhouse gas emissions of the project, the city did not even require common sense measures like rooftop solar,” said Pam Nelson of the Sierra Club’s Santa Margarita Group, which has spent over a year coordinating with the city and other agencies in an effort to ensure the development complies with the law.

The project would install homes within a few feet of the proposed “western bypass” highway in the hills above Old Town Temecula. The western bypass would not only scar these scenic hills, but would expose Altair residents to significant automotive pollution that can lead to higher rates of asthma, lung cancer and premature death.

The conservation organizations repeatedly raised these concerns in comment letters, public hearings and meetings with the city. The city’s approval of the project violates the California Environmental Quality Act, which requires that when environmental impacts are significant, the approving agency must adopt all feasible mitigation measures and alternatives to reduce those impacts. The city’s approval of the project also violates the Western Riverside County Multiple Species Habitat Conservation Plan.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.6 million members and online activists dedicated to the protection of endangered species and wild places.

The Sierra Club is America’s largest and most influential grassroots environmental organization, with more than 2.4 million members and supporters nationwide. In addition to creating opportunities for people of all ages, levels and locations to have meaningful outdoor experiences, the Sierra Club works to safeguard the health of our communities, protect wildlife, and preserve our remaining wild places through grassroots activism, public education, lobbying, and litigation. 

The Mountain Lion Foundation is a national non-profit organization founded in 1986.  For 30 years, the Foundation has worked with member volunteers, activists and partner organizations to create and further wildlife policies that seek to protect mountain lions, people and domestic animals without resorting to lethal measures. For more information, visit

Cougar Connection is a non-profit, public interest organization that is dedicated to the preservation of Puma concolor, Cougar populations, open space, wildlife connectivity, and public education.

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