The Wallis Annenberg Wildlife Crossing is a vegetated overpass currently under construction in Agoura Hills, California, at Liberty Canyon. Originally called the Liberty Canyon Wildlife Crossing, the bridge will be a critical wildlife crossing, spannning the ten-lane Ventura Freeway, connecting the Simi Hills with the isolated Santa Monica Mountains.
Over the last several decades, the Santa Monica Mountains's mountain lion population has declined and become genetically isolated, primarily due to the Ventura Freeway that prevents them from moving between the mountains and the Simi Hills to the north. Since 2002, at least a dozen mountain lions have been killed on the freeway (as has one black bear), and GPS tracking collars show that most approach the freeway then turn back, while only one was able to repeatedly cross.
In 2020, biologists found the first evidence of physical abnormalities in the isolated population. Wildlife crossings, meant to allow animals to circulate through habitats fragmented by human development, would allow newcomers to bring new genetic material to the area and would also allow mountain lions born in the area a chance to leave, in the case of males before they are killed and in the case of females to prevent future inbreeding.
The Wallis Annenberg Wildlife Crossing will be the first bridge in the California highway system designed specifically for wildlife connectivity. Scientists identified Liberty Canyon, about northwest of downtown Los Angeles, as the best location for the crossing in a 1990 study commissioned by the Santa Monica Mountains Conservancy. The crossing is situated along a wildlife corridor within the Santa Monica Mountains National Recreation Area that consists of thousands of acres of local, state, and federally protected lands that stretch from Los Angeles into Ventura County.
Other species expected to benefit from this crossing include bobcats, coyotes, gray foxes, birds of prey, skunks, rodents, American badgers, American black bears, fence lizards, and mule deer.
In 2015, the Resource Conservation District of the Santa Monica Mountains published a design for a and overpass for the wildlife crossing. To encourage use by wildlife, the bridge will have lush but drought-tolerant vegetation with matte materials to deflect bright headlights and insulation to quiet the roar of cars. Fencing at each end will help funnel them onto the crossing. A second phase of the project will cross a frontage road that is parallel with the freeway.
Landscaping of the nearly includes of habitat restoration in the area. The restoration is partially needed because the 2018 Woolsey Fire burned through the wildlife corridor as it was pushed by strong Santa Ana winds in a southerly direction, and crossed the freeway in this area.
The draft environmental document was released in 2017. A tunnel was considered as an alternative, but it would be less able to attract usage by wildlife and wouldnâÂÂt sustain vegetation. The California Department of Transportation (Caltrans) oversaw design and construction as it crosses a major transportation route.
In 2014, the National Wildlife Federation, the Santa Monica Mountains Fund, and the #SaveLACougars campaign began to raise money for the project. The inspiration for the project, as well as the funding drive's "poster puma", was P-22, a mountain lion that survived crossing two freeways, the 101 and the 405, to reach Griffith Park at the easterly end of the Santa Monica Mountains. P-22 became a local celebrity; his death in 2022 would further stimulate awareness and funds for the campaign.
In 2014, the California Wildlife Conservation Board gave a $650,000 grant to the Resource Conservation District of the Santa Monica Mountains for the design of the crossing.
In 2015, the California Coastal Commission gave a $1 million grant to Caltrans for environmental assessment. Private donors were encouraged to contribute. The project stalled for years due to lack of funding. In May 2021, the Annenberg Foundation pledged to donate another $25 million once the project raised $35 million. As of mid-April 2022, donations totaled more than $87 million, with more than 5,000 people, foundations, agencies, and businesses contributing expertise and donations.
The project costs around $90 million, with funding from private donations covering about 60% and the rest coming from public funds set aside for conservation purposes.
In February of 2026 Governor Newsom announced that an additional $18 million would be provided by California from general funds in addition to the funds allocated by the California Transportation Commission from the Environmental Enhancement and Mitigation Program. This changes the funding to 40% from private donations and the rest coming from public funds.
A groundbreaking ceremony was held on Earth Day in April 2022 with Governor Gavin Newsom, Wallis Annenberg, wildlife biologists and members of the public along with local, state and federal legislators. Caltrans set the beginning of construction for spring 2022 with construction to be completed within two years. Initial work included moving public utilities. As of October 2025, the work was expected to finish by fall of 2026.
By early 2026, the construction project was $21 million over budget. Project managers blamed weather and tariffs imposed by the Trump administration for the overruns and delays.