Wallis Annenberg Wildlife Crossing, Wildlife bridge in Agoura Hills, California, US

The Wallis Annenberg Wildlife Crossing is a vegetated overpass under construction at Liberty Canyon in Agoura Hills, California, about 35 miles northwest of downtown Los Angeles. It spans the ten-lane Ventura Freeway and a two-lane access road, linking the Simi Hills with the Santa Monica Mountains. The design calls for a 165-foot-wide, 200-foot-long bridge with drought-tolerant planting, matte materials to deflect headlights and insulation against traffic noise, plus fencing that funnels animals onto it.

A 1990 study commissioned by the Santa Monica Mountains Conservancy identified Liberty Canyon, about 35 miles northwest of downtown Los Angeles, as the best site for a wildlife crossing. Since 2002 at least a dozen mountain lions and one black bear were killed on the Ventura Freeway there. Groundbreaking took place on Earth Day in April 2022, with construction later delayed by record rainfall and atmospheric rivers.

The crossing grew out of the #SaveLACougars campaign launched in 2014 by the National Wildlife Federation and the Santa Monica Mountains Fund. Its "poster puma" was P-22, a mountain lion that crossed the 101 and 405 freeways to reach Griffith Park; his death in 2022 drew further donations. More than 5,000 people, foundations and businesses contributed to the roughly $90 million project.

The crossing is being built over the ten-lane Ventura Freeway and a two-lane access road at Liberty Canyon in Agoura Hills, about 35 miles (56 km) northwest of downtown Los Angeles. It lies within the Santa Monica Mountains National Recreation Area, so the surrounding protected lands are reached by local trails and roads rather than a dedicated viewing area. Construction began in spring 2022 and has been delayed by flooding, so check current access before planning a visit.

The crossing is named after Wallis Annenberg, whose foundation pledged $25 million in May 2021, released once the campaign reached $35 million. The design was published in 2015 by the Resource Conservation District of the Santa Monica Mountains: 165 feet wide and 200 feet long. A tunnel was studied as an alternative but rejected because it would attract fewer animals and could not sustain vegetation.