The long-awaited Wallis Annenberg Wildlife Crossing — set to span ten lanes of the 101 Freeway in Agoura Hills — finally has an opening date: December 2, 2026.
But why spend $114 million on a bridge no vehicle will ever use? The answer lies in the GPS collar data.
Since 2002, at least a dozen mountain lions have been killed by vehicles on the 101 Freeway as it cuts through the outskirts of Los Angeles. GPS collar data shows that most of them approach the freeway and turn back. Just one ever managed to cross the freeway more than once.
When the US-101 was built, it divided a continuous habitat into isolated fragments, severing the wildlife corridor between the Santa Monica Mountains and the Simi Hills to the north.
For mountain lions, that means higher rates of inbreeding, increased territorial conflict, and dangerously low genetic diversity. In 2020, biologists detected the first physical abnormalities in this isolated population.
The crossing was first identified as a key solution in a 1990 study commissioned by the Santa Monica Mountains Conservancy. Decades passed before the project could secure enough funding to move forward.
How More Than $100 Million Came Together
In 2014, the National Wildlife Federation, the Santa Monica Mountains Fund, and the #SaveLACougars campaign launched a public fundraising drive.
The project’s most powerful symbol was P-22, a mountain lion that managed to cross both the 101 and 405 freeways to reach Griffith Park, at the eastern edge of the Santa Monica Mountains. His story became a symbol of the connectivity crisis facing California wildlife. His death in 2022 gave the campaign renewed urgency.
For years, the project stalled due to a lack of funding. The turning point came in 2021, when the Annenberg Foundation pledged a conditional $25 million to the National Wildlife Federation’s #SaveLACougars campaign — funds that would be released once the project raised an additional $35 million. It was the largest single donation in the federation’s history.
By mid-April 2022, donations had surpassed $87 million, with more than 5,000 individuals, foundations, agencies, and companies contributing money or expertise. Corporate donors included Boeing, which gave $1 million. Altogether, the campaign raised more than $100 million.
Public funding also played a key role, with major contributions from the California Wildlife Conservation Board, the Santa Monica Mountains Conservancy, the California State Coastal Conservancy, and the state of California. Additional private support came from the Annenberg Foundation and other philanthropic donors.
In February 2026, Governor Gavin Newsom announced that the California Transportation Commission had allocated an additional $18.8 million from the Environmental Enhancement and Mitigation Program.
A Structure That Goes Far Beyond a Conventional Bridge
When construction began in 2022, the budget stood at $90 million, and completion was expected by 2025. Neither target was met.
The price climbed to more than $114 million, driven by inflation, labor shortages, and the complexity of the construction. Record rainfall in 2023 saturated the ground and disrupted compaction work, forcing crews to redo it entirely.
Tariffs imposed by the Trump administration raised the cost of imported materials. The Federal Highway Administration’s National Highway Construction Cost Index rose 60% over the same period.
Project organizers defended the costs, noting that this was no ordinary bridge. Engineers are building a living ecosystem over ten lanes of one of the busiest freeways in the country — a task requiring specialized soils, acoustic barriers, native vegetation, and landscape features designed to funnel animals toward the crossing.
The crossing is 210 feet wide and planted with native species chosen for specific ecological roles. These include California sage, oaks, sycamores, native grasses, and plants that provide habitat for monarch butterflies and other pollinators. Every species was selected to ensure the corridor blends seamlessly into the surrounding habitat.
The structure isn’t yet fully grown in, but wildlife is already responding. According to Beth Pratt, California regional director for the National Wildlife Federation, multiple butterfly species and at least eight bird species — including red-tailed hawks and American kestrels — have already been spotted on or above the structure.
Beyond mountain lions, the crossing is expected to benefit bears, bobcats, foxes, coyotes, and deer — all species frequently killed by traffic on the 101.
The organization behind the project has launched a public poll asking which animal people think will be the first to cross.
December 2026: The Date Conservationists Have Been Waiting Years For
The Wallis Annenberg Wildlife Crossing is scheduled to open on December 2, 2026. It will be the first dedicated wildlife crossing over a California freeway — and the largest of its kind in the world.
When it opens above the 101, the crossing will restore a critical wildlife corridor through the Santa Monica Mountains and could pull the local mountain lion population back from the edge of extinction.
Organizers are already citing the project as a model for future wildlife crossings across Southern California and in urban areas around the world, proving that human engineering can create structures as fascinating as the iconic stone bridge Rakotzbrücke.
