It was a balmy Los Angeles evening in February 2012 and wildlife biologist Miguel Ordeñana was seated behind a glaring screen, ritualistically flipping through trail-camera photos captured in California's Griffith Park. As Ordeñana scrolled through a seemingly endless gallery of raccoons, rabbits, and "deer butts", he came across something truly startling: the unmistakable rear end of a mountain lion. "It was like finding Bigfoot," he recalled in P-22: The Cat That Changed America, a documentary about the now-famous puma. This was the start of life in the limelight for the Griffith Park puma, a celebrity cat who has become the face of conservation in Los Angeles and a prime motivator in efforts to build the world’s largest wildlife crossing.

Griffith Park – a 4,310-acre green haven at the eastern end of the Santa Monica Mountains – is flanked on all sides by busy highways and residential homes. The idea of a mountain lion secretly stalking through the popular recreational hangout seemed implausible if not impossible. But Puma 22 or P-22 – a name given to the cat by biologists working with LA's mountain lions – shifted all expectations.

Since his discovery, like many Hollywood hopefuls before him, the "Brad Pitt of pumas" shot to stardom and quickly become ingrained in Los Angeles culture. "Since that first headline in 2012 announced 'Mountain Lion in Griffith Park,' P-22 and his cougar kin in the area have enjoyed increasing celebrity around the world," Beth Pratt, the California director for the National Wildlife Federation and driving force behind the #SaveLACougars campaign, explained to us via email.

Steve Winter's now-famous photo of the cat strolling down a trail with the Hollywood sign visible in the background helped boost P-22's public image, as did Tony Lee Moral's documentary which captivated audiences across the country (and globe). "P-22 truly is the cat that changed America, and the world – that isn’t just hyperbole," Pratt adds.

Shortly after he first turned up on a trail cam, wildlife biologists captured and collared P-22 as part of an ongoing study on California's mountain lion populations. Genetic samples revealed that he was likely born in the Santa Monica Mountains. To reach Griffith Park, the famous feline had to cross two major highways – a challenge that, for many other cats like him, has ended in tragedy.

So while P-22's road-crossing skills elevated him to celebrity status, his story underscores a darker narrative - one in which mountain lions are tackling grave threats. California is home to at least 10 genetically distinct subpopulations of pumas, and many of them suffer from low genetic diversity as they fight to survive in the shadow of human development. Los Angeles is one of only two megacities in the world that are home to big cats and the mountain lions that live in this highly urbanised space have the odds stacked against them.

Unless something is done to improve the genetic diversity of LA's cougars, the species could face local extinction within decades, according to a recent study. LA is crisscrossed with busy freeways that make it risky for wildlife to navigate their way through the remaining pockets of suitable habitat. "Simply put, we won’t have mountain lions in the Santa Monica Mountains in the future if we don’t connect the landscape," Pratt points out. P-22 and his kin in the greater LA area, especially those south of the 101 freeway, are likely to go extinct in the near future unless they can connect with cats outside of their bloodlines. "The science is now clear that wildlife need large landscape connectivity in order to have a future," writes Pratt.

P-22's celebrity status helped raise awareness about the plight of LA's mountain lions.

Just last year, the National Park Service announced the first evidence of physical abnormalities likely to be the result of inbreeding found in the Santa Monica mountain lion population. It's a critical discovery that confirmed what conservationists already feared: the pumas will probably not survive unless something changes quickly.

Life for P-22 and other cats like him is exceedingly difficult and unlikely to improve without intervention. So conservationists came up with an ambitious plan: build a giant bridge. For almost a decade Pratt has been working on a fundraising campaign to help construct a 200-foot wildlife crossing spanning the 10-lane 101 freeway. The Liberty Canyon crossing will be the largest of its kind in the world and comes with an $85-million price tag. It's a tall order, but helped – in no small part – by a recent $1.4-million donation from a private funder, the project has reached the $18-million mark and groundbreaking is in sight.

"The incredible support of people from around the world has allowed us to advance this project from a visionary idea to an impending reality," Pratt stated in a press release on the National Wildlife Federation's website. "This past fall, we released new design visualizations, Caltrans [the California Department of Transportation] will have the blueprints for the crossing completed this summer, and if fundraising remains strong, we will break ground in November."

While puma conservation is the driving force behind the proposed wildlife crossing, an array of other species including deer, raccoons, coyotes, skunks and squirrels are expected to also benefit. For Jeff Sikich, a wildlife biologist who has been studying LA's cougars since the early 2000s, P-22's fame provides an opportunity to spread a broader conservation message while also saving the cats that have become icons of California's urban spaces. "By telling P-22’s story, we can inject a lot of the conservation messages we want to get out to the public. Being trapped in this little park, we can talk about habitat fragmentation and the need for corridors," he tells The Guardian.

As long as P-22 continues to captivate the pubic imagination, conservation projects have a greater chance of succeeding. The famous cat was recently recaptured by National Park Service biologists who changed the batteries on his GPS collar and gave him a routine health check. "For an old cat, P-22 stillz got it going on!” read an update on the Santa Monica Mountains National Recreation Area’s Facebook page

Wildlife biologists regularly recapture P-22 to heck his health and to replace the batteries in his GPS collar. This footage is from a routine procedure carried out in 2015.

For conservationists like Beth Pratt and Miguel Ordeñana, P-22 is a life-changer. "As someone who grew up in Los Angeles just down the street from P-22's future home, his story is very personal for me and changed my relationship with nature," Ordeñana tells us via email. "He has challenged me to search deeper in LA's urban core for species that we normally don't expect to be there. As a minority in the sciences, I am always looking for ways to make urban nature seem more relatable and interesting. His story is a story of survival and overcoming seemingly insurmountable odds ... I know he will never understand how famous or impactful he's been but it is hard to believe that there could be another individual animal that will ever have such an impact on so many people on a personal level and be the spark for a conservation movement."

Pratt feels a similar personal connection to California's most famous cat: "He helped shift my perspective on how we should share our human spaces and why wildlife conservation in urban areas is critical. And for me he represents perseverance. Here is an animal that is holdover from the ice age, now living under the symbol of our modern age, the Hollywood sign, who is somehow surviving despite the odds. He is quite a remarkable cat. And his legacy truly will be ensuring the survival of his species in the LA area, and changing minds about urban wildlife worldwide. Not bad for a small town cat."

For a more detailed look at P-22's remarkable story and the proposed wildlife crossing that he's become synonymous with, take a look at Tony Lee Moral's documentary P-22: The Cat That Changed America, or get your hands on the recently released children's book with the same title.


Editor's note: A previous version of this article stated that LA's cougars could face extinction within 50 years – this has been altered for accuracy.
The number of years that Beth Pratt has been working on the fundraising campaign was also adjusted from five years to "almost a decade".