A wildlife crossing is under construction above the 101 Freeway northwest of Los Angeles to conserve Southern California mountain lions and other animals.
The Wallis Annenberg Wildlife Crossing project began on Earth Day, April 22, with a groundbreaking ceremony that paved the way for completion in 2025.
Watch Live: Animal Crossing Construction Site Cameras
The green space bridge will provide more space for mountain lions and other animals constrained by urban sprawl. Big cats, coyotes, deer, lizards, snakes and other creatures have a safe route into the vastness of the Santa Monica Mountains and greater access to food and potential mates.
Here you can find out what you should know about bridge construction, lane closures and more.
Where is the animal crossing?
The intersection will span the 101 Freeway in Liberty Canyon near Agoura Hills. About 300,000 cars travel daily on this section of 101 in Agoura Hills, a small town surrounded by a patchwork of protected wilderness that the new intersection will connect.
Riders in the Liberty Canyon area will hurtle under the bridge, which is 165 feet wide and is topped with shrubbery and trees that seamlessly connect to the slopes on either side of the lanes.
Click here to view renderings of the project.
When does the Wallis Annenberg Wildlife Crossing open?
The construction work will take place mostly at night and will not require lengthy shutdowns of the 101 freeway, officials said. Completion is scheduled for early 2025. It will be the world’s largest crossing of its kind – a fully landscaped wildlife crossing that will span 210 feet across 10 lanes of highway and sidewalk.
A live feed of the construction site above the 101 Freeway in Agoura Hills is available here.
The architects designed the topography so that it is indistinguishable from the landscape on either side. High-edged berms and troughs block sound and light from the lanes below.
Why is the wildlife crossing being built?
It is estimated that without an influx of genetic diversity, the mountain lion population in the Santa Monica Mountains could become extinct within 50 years. The lions are largely isolated due to highways that act as barriers to movement in the region.
Conservationists hope the $85 million crossing will alleviate the problem.
Five mountain lions were killed this year trying to cross highways in Southern California.
“This wildlife crossing couldn’t have come at a better time,” said Jeff Sikich, a wildlife biologist with the National Park Service.
The star of the fundraiser was the Mountain Lion P-22. Famous for traveling two freeways and making a massive Los Angeles park her home, the big cat has come to symbolize the shrinking genetic diversity of wild animals that, through widespread development, are all but trapped or at risk of to be run over.
Vehicles and toxins, such as rat poison, are two of the biggest threats to mountain lions in Southern California.
In June, mountain lion P-54, part of a National Park Service mountain lion study, was struck by a vehicle in the Malibu area and killed. The mountain lion and her four kittens also tested positive for several anticoagulant rodenticides or rat poisons.
The next month, two-year-old mountain lion P-89 was struck and killed on the 101 freeway in the western San Fernando Valley. He was the fourth big cat from the group study to be killed on a Southern California street this year.
Scientists tracking cougars equipped with GPS collars over decades found that roads running along the Malibu coast and across central LA to Griffith Park, where P-22 made its home, mostly contained animals in mountains imprison. Although P-22 is the face of the project, he probably won’t use the bridge as he’s confined to the park many miles away.
But many of his relatives could benefit from it.
“Just a single adult male coming here every few years is enough to maintain some genetic diversity,” Sikich said.
The idea is not new, but what makes this project special is that it sits above one of the busiest highways in the world. The bridge will span 200 feet over 10 freeway lanes and one feeder road just 35 miles northwest of downtown Los Angeles.
Who pays for the wildlife crossing?
About 60% of the $90 million prize is covered by private donations, with the remainder coming from public funds earmarked for conservation purposes. The span is named the Wallis Annenberg Wildlife Crossing, after the philanthropist whose foundation donated $25 million.
Wildlife crossings – bridges and tunnels – are common in Western Europe and Canada. A famous one in Alberta’s Banff National Park straddles the Trans-Canada Highway and is commonly used by bears, moose, and elk.
The Los Angeles-area bridge has enjoyed near-universal support, unusual for a public works project. The draft environmental impact document received nearly 9,000 comments – only 15 opposed it, according to the wildlife association.
There are about 4,000 to 6,000 mountain lions in California, but wildlife officials call that a rough estimate without an ongoing statewide study. More than half of the state is considered prime habitat for big cats, which can be found wherever deer are found.
The California Department of Fish and Wildlife receives hundreds of mountain lion sightings each year. Few lead to mountain lions being identified as an imminent threat to public safety, the department said. Mountain lion attacks on humans are extremely rare and their nature is to avoid humans.