Wildlife Crossing Takes Shape As 101 Freeway Bridge Reaches Milestone

AGOURA HILLS, CA — The project to build a wildlife crossing over the 101 Freeway reached a major milestone Tuesday after crews completed the installation of 82 enormous beams that will eventually support the tons of soil and plants that will make up the nation's largest wildlife bridge.

Following over a month of daily overnight lane closures on the 101 Freeway, crews on Tuesday placed the final support beam, or girder. Each of the girders weighs between 126 and 140 tons, stretching from the center median to the freeway shoulder, according to Caltrans.

⚠️WALLIS ANNENBERG WILDLIFE CROSSING⚠️ Caltrans Transportation Engineer Max Moheb (orange sweatshirt w/black trim on bottom) gives #VenturaCollege engineer students lesson on intricate details involved in building bridge over US 101 in Agoura Hills. pic.twitter.com/XT2wv8bO6K
— Caltrans District 7 (@CaltransDist7) May 20, 2024

All southbound lanes of the 101 Freeway were set to be closed between Cheseboro and Liberty Canyon roads between 11 p.m. Tuesday and 4 a.m. Wednesday so crews can remove the large crane that was used to install the girders over each side of the freeway.

No additional overnight closures in the area are immediately planned now that the girder work has been completed.

With the installation of the girders, the scope of the ambitious project is beginning to come into view: The structure will support a fully landscaped crossing that will span over all 10 lanes of the freeway. The crossing is meant to connect the small population of mountain lions in the Santa Monica Mountains and the larger, more genetically diverse populations to the north.

Construction began in 2022 and is set to be completed either next year or in early 2026.

Decades of road construction and development have been deadly for animals trying to cross the area's freeways, while creating islands of habitat that have genetically isolated wildlife ranging from bobcats to birds and lizards.

Wildlife advocates hope the crossing can save the threatened local population of mountain lions from extinction, which could become inevitable if lions continue a historic pattern of inbreeding due to the limited numbers of cats in the area.

City News Service contributed to this report.