The Wallis Annenberg Wildlife Crossing is a wildlife infrastructure project under construction in Southern California. The project is intended to provide a safe passage for wildlife across U.S. Highway 101 and improve habitat connectivity between natural areas on either side of the roadway.
The crossing is being built in the Conejo Valley region, which spans portions of Ventura County and Los Angeles County. According to project plans, the structure will measure approximately 210 feet in length and 165 feet in width upon completion.
Construction began in April 2024 with the installation of reinforced concrete girders that form the structural base of the crossing. More than 80 girders are planned for the project, supporting the bridge as it spans across U.S. Highway 101.
Project works have required temporary overnight closures in the Liberty Canyon area to facilitate girder installation. According to project information, a total of 82 girders, each weighing between 126 and 140 tons, were scheduled for installation across the southbound and northbound lanes of the highway.
Latest Updates
At the time of the project update, completion of the wildlife crossing was expected in early 2025. Latest updates in 2026 note that the Wallis Annenberg Wildlife Crossing is scheduled to officially open and hold its ribbon-cutting ceremony on December 2, 2026. The $114 million project, which spans the 101 Freeway in Agoura Hills, California, is nearing completion. Moreover, it is already teeming with native plant life and small wildlife.
Other Projects
Another major bridge project that will also have an impact and is advancing is the Blatnik Bridge replacement in Minnesota. The Minnesota and Wisconsin transportation departments have named Ames-Kraemer Joint Venture II as preferred contractors for the project. The bridge is a vital freight and commuter link between Duluth, MInn. And Superior, Wis. Virginia-based global infrastructure provider Parsons Corp. will provide design and construction oversight contracts for the project.
Moreover, construction is slated to start in late 2026 and be completed in 2031. Parsons previously provided preliminary engineering design for bridge replacement. A public meeting will be held in early September to give an update on the project including details on the design of the new bridge, according to the transportation depts.
Unique features of the Wallis Annenberg Wildlife Crossing
The size of the Wallis Annenberg Wildlife Crossing is reportedly not the only unique aspect about it as it is designed to seamlessly integrate into the mountains, offering big cats, coyotes, deer, lizards, snakes and other creatures a safe way to travel to different parts of the 150,000-acre open territory in the Santa Monica mountains recreation area.
According to Robert Rock, a landscape architect with Living Futures in Chicago who led the bridge design, this nature-centred type of construction makes it unlike other wildlife bridges and underpasses around the world, which are typically made of cement and steel.
According to Rock, the Wallis Annenberg Wildlife Crossing design team included a soil scientist who collected soil samples nearby that are specific to the local trees as well as a mycologist who studied the fungi of the area and how they can help the seamless flow of plants and animals across the overpass.
As both a tool for and a symbol of connection, Rock believes that the world’s largest wildlife crossing will stand as an alluring challenge to future generations to pick up the mantle of design to bridge the gaps elsewhere in our world.
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Cost and funding for the world’s largest wildlife crossing
The Wallis Annenberg Wildlife Crossing project is developed through a public-private partnership. The core partners include Caltrans, the National Park Service, the Santa Monica Mountains Conservancy, the Mountains Recreation and Conservation Authority, the Resource Conservation District of the Santa Monica Mountains, and the National Wildlife Federation.
The cost of implementation of the project is estimated to be US$ 92 million or its thereabouts. Private donors contributed half of the estimated cost with Wallis Annenberg, whom the bridge is named after contributing US$ 26 million and around 6000 other donors contributing the other part of the private donations.