World's Largest Wildlife Overpass In the Works in Los Angeles County

Caltrans will soon close half of the 101 Freeway in order to continue construction of the Wallis Annenberg Wildlife Crossing near Agoura Hills in Los Angeles County.

2 minute read

April 15, 2024, 9:00 AM PDT

By Clement Lau


Rendering of wildlife crossing over 101 freeway in Los Angeles County.

The Wallis Annenberg Wildlife Crossing will provide a way for animals to cross the 101 freeway. | Annenberg Foundation / Wallis Annenberg Wildlife Crossing

Located at Liberty Canyon and the 101 Freeway, the Wallis Annenberg Wildlife Crossing is a public-private partnership that has leveraged the expertise and leadership of numerous organizations and institutions. The core partners include Caltrans, the National Park Service, the Santa Monica Mountains Conservancy, Mountains Recreation and Conservation Authority, Resource Conservation District of the Santa Monica Mountains, and the National Wildlife Federation.

The purpose of the project is to provide a safe and sustainable passage for wildlife across the 101 Freeway near Liberty Canyon Road in Agoura Hills to reduce wildlife death and allow for the movement of animals and the exchange of genetic material. Without a safe and sustainable wildlife crossing, movement between these remaining areas of natural habitat is severely restricted and wildlife within the Santa Monica Mountains is essentially trapped.

As reported by Makenna Sievertson in this article, Caltrans will be closing all southbound lanes of the 101 Freeway in Agoura Hills for five hours each night for construction on the wildlife crossing starting Monday, April 15th, 2024. Specifically, crews will be installing the first girders, an approximately 100-foot-long box of reinforced concrete that will serve as the base level of the wildlife crossing. The girders will help support the structure’s horizontal reach across one of the country’s busiest highways.

The closure will extend from Liberty Canyon to Chesebro roads, but the northbound lanes will remain open and there will be detours available for drivers. Breaking ground on Earth Day in 2022, the project is anticipated to be completed by early 2026. For additional information, please read the source article.

Friday, April 12, 2024 in LAist

Young Professional

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban and Environmental Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban and Environmental Planner

Get top-rated, practical training for planners

"Planetizen federal action tracker" logo superimposed over black and white image of US Capitol dome.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

October 28, 2026 - Zachary Whalen

A car drives through a puddle, making a large splash. Rain pours down.

California plans to bury El Niño’s downpour

If the state plays its cards right, it may be able to store a billion acre-feet of El Niño’s water in aquifers.

October 28, 2026 - Grist

A pencil rendering of Foundry Park, which shows skyscrapers and public green spaces.

Chicago breaks ground on $3 billion megadevelopment

The new neighborhood, titled Foundry Park, will one day host 3,700 residences.

October 23, 2026 - Chicago Sun Times

A swamp in South Carolina with tall pale trees and Spanish moss in the water.

Satanic Place Names

From streams and lakes to valleys and canyons, I mapped more than 1,000 places named after the Devil.

October 31 - The Daily Yonder

A rendering of a high speed rain station in California, with wide platforms and a sleep train with yellow highlights.

California High-Speed Rail Authority CEO resigns after $600,000 scandal

Under Ian Choudri, the authority used taxpayer dollars to fund first class flights and trips to nightclubs.

October 30 - Cal Matters

 A bridge stretches across the Missouri River at Chamberlain, South Dakota.

Want to study the Missouri River? Soon, you may need unanimous approval from 10 states

Legislation would require 10 governors’ permission to study or build projects moving water outside the basin.

October 30 - South Dakota Searchlight