Wallis Annenberg Wildlife Crossing

The Wallis Annenberg Wildlife Crossing is a vegetated overpass system currently under construction in Agoura Hills, California, at Liberty Canyon. Originally called the Liberty Canyon Wildlife Crossing, the overpass will be a critical wildlife crossing, spanning the ten-lane Ventura Freeway, connecting the Simi Hills with the isolated Santa Monica Mountains. The project includes two bridges, earthwork, and 13 acres (5.3 ha) of habitat restoration. Background 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 35 miles (56 km) 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. Design In 2015, the Resource Conservation District of the Santa Monica Mountains published a design for a 165-foot-wide (50 m) and 200-foot-long (61 m) 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 1-acre (0.40 ha) bridge includes 12 acres (4.9 ha) 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 wouldn’t sustain vegetation. The California Department of Transportation (Caltrans) oversaw design and construction as it crosses a major transportation route. Funding campaign 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 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. Construction 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. A delay to construction was announced in 2024 due to flooding. The project is a joint public and private effort funded by the Annenberg Foundation, private donations, and state and local donations. By early 2026, the construction project was $21 million over budget due to a variety of factors. Project managers and public advocates for the project stated that it was delayed, first citing record rainfall in the 2022–2023 California floods, which interrupted ground-compaction work which had to be redone in 2023, and then subsequently after the February 2024 California atmospheric rivers event. Managers also stated that tariffs imposed by the Trump administration caused cost overruns, as materials required to build the bridge were sourced from overseas and thus subject to tariffs, raising their prices. SFGate also cited the National Highway Construction Cost Index, calculated by the Federal Highway Administration to track the change in construction of highways increased by 60% across the board. As of April 2026, the work was expected to finish by November 2026. References External links Wallis Annenberg Wildlife Crossing, Annenberg Foundation US-101 – Wallis Annenberg Wildlife Crossing at Liberty Canyon, Caltrans Wildlife Crossing at Liberty Canyon, Resource Conservation District of the Santa Monica Mountains Liberty Canyon Wildlife Crossing, Santa Monica Mountains Conservancy Liberty Canyon Wildlife Crossing, Save Open Space, Santa Monica Mountains Liberty Wildlife Corridor Partnership (savelacougars.org) The building of the world’s largest animal crossing, Michelle Loxton, KCLU, April 1, 2022 (podcast)