While state and local groups keep pushing for wildlife mitigation studies to help Orange County’s dwindling mountain lion population, there are mounting concerns the effort may not pay off in time to avoid extinction.
This year alone, a mountain lion has died roughly once a month across Southern California, with six of the seven fatalities being vehicle related.
Just this past weekend, another adult mountain lion was killed along Ortega Highway in South Orange County, according to Fernando Najera, head of UC Davis’ Mountain Lion Project.
Mountain lions have been getting fatally struck at a consistent rate across Orange County.
A mountain lion was struck on the 241 toll road last July.
Then a mother mountain lion was struck on Ortega three months later in September.
[Read: Can Two Orphaned 14 Month Old Mountain Lion Cubs Survive Orange County?]
Four months later one of her cubs was struck on Ortega.
[Read: Lack of Fencing Along Ortega Highway Kills Two More Mountain Lions in OC]
And then in March another juvenile was killed, also on Ortega.
This year began with a mountain lion death on Santiago Canyon Road in January.
And now another this past weekend, once again on Ortega Highway.
Orange County is now down to between 52 and 67 lions depending on varying counts – making them some of the most threatened in California.
For reference, the mountain lions of the Eastern Peninsular Range – an adjacent subpopulation stretching through San Diego, Riverside and Imperial Counties – are estimated to number between 297 and 459.
In Northern California, mountain lions are thriving.
“Large areas of the state appear to have robust, genetically diverse and well connected populations,” reads a December 2025 status review from the California Department of Fish and Wildlife on the species, referring to two large subpopulations of mountain lions in Northern California.
Meanwhile, the report notes that “other populations show evidence of inbreeding depression and genetic isolation,” referring to the local mountain lion populations in The Santa Ana and the Santa Monica Mountain ranges.
A map showing the different sizes and ranges of mountain lion subpopulations across California. Orange County mountain lions are represented by the grey-blue portion at the bottom-left of the map. Map courtesy of CDFW.
There’s several reasons why Orange County’s mountain lion population is thinner than other parts of the state.
Dealing with Roadway Deaths
One of the most prominent and persistent threats to mountain lions across all of Southern California continues to be local roads and highways.
In Orange County, Ortega Highway has been one of the recent hotspots for mountain lion collisions, where one was just killed this weekend.
The state’s transportation agency, Caltrans, began a study just last month in an attempt to mitigate threats.
“During the study, Caltrans will evaluate Ortega Highway to identify potential locations and wildlife crossing designs that could be implemented to benefit wildlife connectivity in the area,” said Caltrans Public Information Officer, Robert Johnson in a July 30 email statement.
“If a concept is determined to be feasible, Caltrans may advance it as part of a future transportation project. If that occurs, the project would undergo the environmental review process, during which Caltrans would open up the project to public review and provide an opportunity for comments and feedback,” added Johnson.
However, getting Orange County’s mountain lions studied hasn’t been easy.
Internal email communications reviewed by Voice of OC where Caltrans was working with other agencies to coordinate a separate study, illustrated local struggles with the state transportation agency.
One official, Leslie Hill, an environmental oversight specialist for the Orange County Transportation Authority, expressed concerns about state transportation officials’ commitment to Orange County in a December 3, 2025 email.
“It’s been a struggle to get their (Caltrans) headquarters to support the project,” Hill said in an internal email conversation that included Caltrans and OC Public Works officials, adding “Headquarters needs to approve the projects that they go after for grants and they seem to be favoring bigger bridge-like crossing projects in the state.”
Bridge-like crossings, Hill remarked, may take too long to be effective – time that OC mountain lions don’t have.
“We are concerned that while waiting for a big infrastructure project to get studied, funded and built we could lose our local mountain lion population,” said Hill.
Caltrans acknowledges these concerns but officials hope that through a combination of long term and short term projects, they will be able to mitigate threats in an effective manner.
“Large infrastructure projects can provide substantial benefits for wildlife movement,” said Caltrans Spokesman Robert Johnson, adding, “At the same time, we recognize these larger projects can take time to develop and deliver. That’s exactly why Caltrans explores additional approaches to advance wildlife connectivity through standalone efforts like the feasibility study on Ortega Highway.”
Scrapping for Land
Orange County’s mountain lions not only have to compete with each other for territory but also against development.
According to a 2019 study from The Journal of Wildlife Management, half of the lands suitable for mountain lion territory in the state were on unprotected lands.
Officials that study mountain lions across California point to local highways like the 5 and the 91, combined with the ever expanding presence of humans as factors that have isolated OC’s mountain lions from others across the region.
It’s a notion proven through GPS data.
A 2025 status review from the state wildlife agency for the species noted that, “GPS data from collared mountain lions in the Santa Ana Mountains have revealed that on multiple occasions lions approached one of the three regional freeways (the 5, 15 and 91), only to range back and forth along them before turning back.”
This isolation takes its toll on local populations, making many young adolescent mountain lions unable to disperse, creating inbreeding and territorial issues.
It makes it even harder for these struggling populations to grow.
“These populations are dependent on young males who leave their mothers trying to find territory,” said former director of the UC Davis Mountain Lion Project, Winston Vickers in an interview, adding, “They also have fairly high mortality rates because they’re crossing a lot of strange territory, they’re crossing highways they’re not familiar with.”
Orange County’s mountain lions are incredibly boxed in on all sides. Because of this confinement, inbreeding and by extension lower genetic diversity are much more common.
The resulting inbreeding has also had documented impacts on the population with scientists noting evidence of kinked tails and abnormal sperm production in individuals, which is one of the first signs associated with decreased reproduction and population decline.
Some work is being done to combat this.
For example, according to the Orange County Transportation Authority, through the Measure M Environmental Mitigation Program, officials have permanently protected more than 1,300 acres of open space across Brea, Laguna Beach, Silverado Canyon and Trabuco Canyon.
[Read: Restoring Orange County’s Native Habitat]
Transportation agency officials also mention that through this program, OCTA has funded 13 habitat restoration projects that cover nearly 350 acres of land in Orange County.
However, ongoing land use policies remain a pressing issue as the recent development of the Prima Deshecha Landfill in San Juan Capistrano is also raising concerns with local activists.
[Read: Could Orange County’s Landfill Expansion Threaten Mountain Lions]
Tracking Mountain Lion Fatalities
While mountain lions are an incredibly important species to Orange County’s ecosystem as top predators, it doesn’t seem that local officials have a realtime sense of mountain lion deaths or where they are dying.
Getting information about local mountain lion fatalities is remarkably difficult – evidenced by internal email communications reviewed by Voice of OC that makes it seem like no one knows who is keeping track.
In released communications between OCTA, OC Public Works and Caltrans, officials seem not to know where or who has this important piece of data.
[Read: Was OC Public Works Hiding Internal Talks About Threatened Mountain Lions?]
Email correspondence reviewed by Voice of OC, shows that OC Public Works believes that OC Animal Care is keeping track of road kill records.
However, when contacted, OC Animal Care said that they do not keep any mountain lion specific records and that it would be up to the state.
The California Department of Fish and Wildlife, which also coordinates with UC Davis on their Mountain Lion Project, confirmed they keep track of lion deaths across the state.
Fernando Najera – who heads up the mountain lion project for UC Davis – was able to confirm 39 mortalities across the region of Southern California from 2022-2025 and seven mountain lion deaths this year alone.
However, these numbers are regional, so finding OC specific numbers is still difficult.
California Fish and Wildlife officials confirmed for this story that they rely on reported incidents for their numbers, which makes it possible for deaths to slip through the cracks.
“We had 2 incidents reported to our department from Orange County in 2025, but that doesn’t mean there weren’t others that weren’t reported to us,” reads an Aug. 21 email from California Department of Fish and Wildlife Spokesman Cort Klopping.
Additionally, in response to follow up questions, Klopping said that the county is in fact the one responsible for handling roadkill, and should by extension have a higher count of vehicle and mountain lion fatalities.
Supporting Ecosystems
As a keystone species, mountain lions are incredibly important and necessary ecosystem engineers for Orange County.
Mountain lions work not only to keep other species in check, but to also make sure other species are healthy.
“They tend to prey on the weaker or the sicker animals in a population and so that helps to keep the prey population from having more illness than they otherwise would,” said the retired UC Davis mountain lion project director Vickers, who studied OC mountain lions for decades.
As an example, Vickers said mountain lions will target deer with chronic wasting disease over healthy deer, keeping their populations healthy.
The carcasses left behind by mountain lion kills also work to provide more food for other animals, passing the nutrition down the food chain.
In spite of all the issues facing mountain lions, some activists still hold a hopeful outlook.
“There is a way to find that balance,” said Tiffany Yap, senior scientist and Wildlife Corridor advocate for the Center for Biological Diversity, adding “in California we have a lot of innovation and we have a lot of tools at the ready for us to use, it’s just about implementing them.”
However, other scientists seem less optimistic.
The most recent species status review from California’s Department of Fish and Wildlife includes an ominous warning, noting, “It is estimated that there is a substantial probability of local extirpations (extinctions) within less than 50 years in the absence of efforts to improve habitat connectivity and remove barriers to movement.”
