California construction News staff writer
Construction has entered the final phase on what will soon be the world’s largest urban wildlife crossing, a major infrastructure and conservation project that aims to reconnect fragmented habitat in Southern California.
The Wallis Annenberg Wildlife Crossing, which will span eight lanes of U.S. Highway 101 in Agoura Hills, is expected to be completed by fall 2026. The structure is designed to allow mountain lions, deer, coyotes and other wildlife to safely pass between the Santa Monica Mountains and the Simi Hills, reducing roadkill and increasing genetic diversity among isolated animal populations.
The final phase of work includes extending the structure over a two-lane local road adjacent to the freeway. Crews will also relocate utilities, restore natural hydrology, protect heritage oak trees and move significant amounts of earth to support the structure’s foundation.
“Today, the state is beginning the final phase of construction for what will soon be the largest urban wildlife crossing in the world – all thanks to the visionary work of state, federal, and private partners,” Gov. Gavin Newsom said in a statement. “The Wallis Annenberg Wildlife Crossing will soon protect Los Angeles’ native wildlife and over 300,000 drivers daily, as well as provide a cutting-edge model for urban wildlife conservation.”
The $92 million project is a public-private partnership led by Caltrans, the National Wildlife Federation and other conservation groups. It broke ground in April 2022 on Earth Day and has drawn international attention for its scale and ambition.
The first phase, completed earlier this year, included placing more than 26 million pounds of concrete, installing 82 bridge girders, and constructing sound walls designed to be covered with vegetation. Crews spread 6,000 cubic yards of “living soil” across the bridge deck in preparation for fall planting. More than 50 native plant species will be used to recreate the natural habitat and provide continuous coverage across the crossing.
Supporters say wildlife crossings like this one are key to reducing wildlife-vehicle collisions and restoring ecological connectivity in increasingly developed regions. California officials also see the project as a model for advancing the state’s “30×30” conservation goals — preserving 30 percent of land and coastal waters by 2030.
Real-time construction updates are available to the public through a dedicated webcam hosted by project organizers.
