World’s largest wildlife crossing reaches a new milestone

The Wallis Annenberg Wildlife Crossing—a first-of-its-kind project to reconnect California’s fragmented ecosystems—is moving one step closer to completion. Construction crews have begun placing soil over the massive bridge that will eventually carry wildlife safely over 10 lanes of the U.S. 101 freeway in Agoura Hills.

This milestone marks a major phase in the restoration of a vital ecological corridor—and the start of a new chapter in how California balances infrastructure and conservation.

“California is a state of dreamers and doers – and with the Wallis Annenberg Wildlife Crossing, we’ve turned our dreaming into doing,” said Governor Gavin Newsom. “We’re not only making habitats whole again – we’re making our roads safer.”

A Wildlife Bridge Like No Other

The Wallis Annenberg Wildlife Crossing is set to become the largest wildlife crossing in the world. Once complete, it will serve as a safe passage for species including mountain lions, deer, bobcats, bats, cottontail rabbits, and even monarch butterflies—connecting habitats that have been divided by busy highways for decades.

Crews recently began placing the first layers of 6,000 cubic yards of soil across the bridge deck. This process will continue for several weeks and set the stage for the next step: planting approximately 5,000 native plants in May, weather permitting.

Nature and Infrastructure Working Together

This crossing is more than just a structure—it’s a statement. As Caltrans Director Tony Tavares put it:

“Wildlife crossings are unique because they allow people and nature to thrive together.”

The bridge’s landscaping will feature coastal sage scrub species native to the Santa Monica Mountains, enhancing 12 acres of surrounding open space and supporting the region’s broader biodiversity goals. The project also aims to reduce vehicle-wildlife collisions, making it safer for both animals and drivers.

A Model for Conservation Through Collaboration

Launched on Earth Day 2022, the wildlife crossing is a flagship public-private partnership backed by Caltrans, the National Wildlife Federation, and dozens of other organizations. It reflects California’s leadership in aligning infrastructure, climate resilience, and ecological restoration.

Wildlife crossings like this one play a key role in helping California achieve its 30x30 targets—a statewide goal to conserve 30 percent of lands and coastal waters by 2030. They also represent a growing movement to build connected landscapes that give wildlife the space they need to roam, adapt, and thrive.

The Bottom Line

With soil now being placed and planting soon to begin, the Wallis Annenberg Wildlife Crossing is no longer just an idea—it’s becoming reality. As California continues to lead the way in building infrastructure that supports both people and the planet, this project stands as a powerful symbol of what’s possible when we reconnect with the natural world.