Skip to main content

Wildlife Bridge Planned for 101 Freeway

Support Provided By
Liberty Canyon in the city of Agoura Hills is a wildlife corridor between the Santa Monica Mountains and Simi Hills.
Liberty Canyon in the city of Agoura Hills is a wildlife corridor between the Santa Monica Mountains and Simi Hills. | Photo: Ken Lund/Flickr/Creative Commons License

Caltrans officials plan to build a bridge for mountain lions and other wild animals to cross the Ventura (101) Freeway west of Los Angeles, officials said last week.

The National Park System has been tracking mountain lions in the Santa Monica Mountains since 2002, and its biologists worry that the big cats are inbreeding because they are cut off from other lions in the mountains around Simi Valley and further north.

Caltrans officials announced that a $2 million planning and design grant is being sought from the federal government's infrastructure funding program. Earlier estimates for the wildlife corridor crossing cost were about $10 million.

"The new crossing will better integrate the environment and transportation systems, fostering better wildlife connectivity on either side of the 101, and increasing public safety by reducing the risk for collisions between vehicles and wildlife," said Carrie Bowen, the Caltrans director for Los Angeles and Ventura counties.

Tracking devices have in the past detected lions crossing back and forth over the Reagan (118) Freeway on a little-used road overpass at Rocky Peak. The new 101 overpass or underpass would link two fingers of wild state parkland just west of Liberty Canyon Road in Agoura Hills.

Lions have been killed crossing the 101 at Agoura Hills -- most recently last October -- and attempting to cross the San Diego (405) Freeway at Sepulveda Pass. About 10-15 cougars range from Point Mugu east to the 405, and in one case further east into the Hollywood Hills and Griffith Park, according to NPS biologist Seth Riley.

The latest known litter of cubs, born in the mountains above Malibu, was the product of a male mountain lion mating with one of his daughters, Riley has said.

"If animals can't disperse out, you may be more likely to get close inbreeding, and we've seen a number of instances where fathers have mated with daughters," Riley told KPCC radio last winter.

One male mountain lion managed to cross south across the 101 to seek a mate in the Santa Monica Mountains. He fathered a litter with one Malibu-area cougar, but later mated again with a cub from that litter, Riley said.

The local lions eat deer, and biologists say they are an important part of the biology and ecological balance in the Santa Monica Mountains National Recreation Area.

No attacks on humans in western Los Angeles County have been reported in recent years. But two hikers have been mauled and killed by mountain lions in Orange and San Diego counties in the past two decades.

Support Provided By
Read More
Gray industrial towers and stacks rise up from behind the pitched roofs of warehouse buildings against a gray-blue sky, with a row of yellow-gold barrels with black lids lined up in the foreground to the right of a portable toilet.

California Isn't on Track To Meet Its Climate Change Mandates. It's Not Even Close.

According to the annual California Green Innovation Index released by Next 10 last week, California is off track from meeting its climate goals for the year 2030, as well as reaching carbon neutrality by 2045.
A row of cows stands in individual cages along a line of light-colored enclosures, placed along a dirt path under a blue sky dotted with white puffy clouds.

A Battle Is Underway Over California’s Lucrative Dairy Biogas Market

California is considering changes to a program that has incentivized dairy biogas, to transform methane emissions into a source of natural gas. Neighbors are pushing for an end to the subsidies because of its impact on air quality and possible water pollution.
A Black woman with long, black brains wears a black Chicago Bulls windbreaker jacket with red and white stripes as she stands at the top of a short staircase in a housing complex and rests her left hand on the metal railing. She smiles slightly while looking directly at the camera.

Los Angeles County Is Testing AI's Ability To Prevent Homelessness

In order to prevent people from becoming homeless before it happens, Los Angeles County officials are using artificial intelligence (AI) technology to predict who in the county is most likely to lose their housing. They would then step in to help those people with their rent, utility bills, car payments and more so they don't become unhoused.