
In 2012, Southern California was besotted with an unlikely celebrity: a telegenic mountain lion who had crossed one of the state’s most perilous freeways, seeking a territory to call his own. Widely deemed “LA’s loneliest lion” and “most eligible bachelor,” the chiseled puma in question, named P-22, roamed the bustling but otherwise big cat-less Hollywood Hills, unable to safely return to the home he’d left behind. His search for a mate below the Hollywood Sign rendered him an icon of his city, but also a rueful reminder of the sprawling highways that bifurcated his habitat in the first place, leaving his clan on the other side of I-405 on the verge of local extinction.
Beth Pratt, then recently named head of California’s branch of the National Wildlife Federation, remembers strolling through Griffith Park with the wildlife biologist Jeff Sikich in 2012. Pratt knew that P-22 roamed somewhere nearby, and she found herself wondering aloud how she could help. “Well, there’s this little wildlife corridor we need to get built,” Sikich told her.
“I’m like, ‘Sure, how hard can it be?’” she recalled to me with a laugh. “Well, apparently, it’s quite hard.”
Fourteen years later, the project they discussed that day, now known as the Wallis Annenberg Wildlife Crossing, is finally scheduled to open in December. When it does, it will be the largest real-life animal crossing in the world, a gorgeous, vegetated overpass offering safe passage to local mountain lions, coyotes, deer, and black bears across the perilous 10-lane Ventura Freeway, where P-22 dodged cars back in 2012.
Though P-22 died before he could take advantage of that crossing himself, he helped engender a movement that, hard as it may have been to pull off in LA, could help revolutionize how animals cross America’s most dangerous roads, preventing some of the hundreds of human deaths, hundreds of millions of animal deaths, and billions in damages caused by wildlife collisions each year.
It is a species of elegant, bipartisan infrastructure that, if you squint, might even make you believe in America’s ability to build again, and to build in a way that still lends a hand — a paw, if you will — to the least empowered among us, a stranded salamander or the loneliest of lions.
As Pratt put it: “What’s more hopeful than rewilding one of the world’s busiest freeways?”
Wildlife crossings used to be rare in the US. Not anymore.
When Pratt first pitched the idea for a wildlife crossing across the 101, such projects were still rare in the US, and rarer still across such a major thoroughfare. As she recalls it, California’s transportation agency initially reacted with bafflement when she put the idea forward, a sign of just how novel the project was at the time. That made the process of getting it built more grueling than it needed to be, and likely more expensive, with a final price tag of over $100 million.
But as LA meandered in its quest to build its unprecedented 210-feet-long Wallis Annenberg — beset, Pratt told me, by its complex engineering mandate, a funding model that relied on philanthropy, and the rising costs associated with construction and extreme weather — the rest of the nation took notice. In the 14 years since P-22 first crossed the 101 and the 405, over 1,000 new wildlife corridors have sprouted up across the country, a trend that culminated with the $350 million Wildlife Crossings Pilot Program, created in 2021 as part of the Infrastructure Investment and Jobs Act. Many of these projects were championed by Pete Buttigieg, who was Transportation secretary under the Biden administration, and who told Vox last year that such passages are “not ornamental,” but rather “something that ties into the very core of our mission, which is to secure the safety of the American traveling public.”
America’s burst of new wildlife corridors include a camouflaged overpass for elk crossing Interstate 25 in Colorado; a lush shared land bridge for deer, bobcats, and people passing over a Texan parkway; crossings for alligators passing under I-75 in the Florida everglades; and tiny tunnels under the Atlantic City expressway in New Jersey for migrating toadlets. California’s transportation agency, for its part, now boasts a division explicitly dedicated to building wildlife crossings, though many projects need not be as ambitious as the Wallis Annenberg.
“Sometimes it’s pretty simple,” like a small hole to let hedgehogs through your fencing or a buzz stop for bees and butterflies crossing your lawn, Pratt said. “Sometimes it’s in your own backyard.”
Along the way, a new set of norms have begun settling in at transportation agencies across the country, said Marcel Huijser, a research ecologist at the Western Transportation Institute, who noted that while “road ecology has become more recognized” in the US, the nation still has a very long way to go. Huijser is from the Netherlands, where wildlife crossings have been the norm for decades. The country boasts thousands of them in an area roughly double that of Massachusetts.

“Most other parts of the world have done a better job at taking social and ecological impacts into consideration from the earliest decision processes onwards,” he told me, rather than “making it an afterthought.” And given that highways are already three times more expensive to build and maintain per mile in the US than they are elsewhere, it’s not the cost of conservation alone that has long kept the nation from incorporating such concerns into its road planning.
Instead, as Huijser put it, “the norms, the values, [and] the culture” of the country have, until recently, ensured that planners rarely baked ecological considerations into the way it imagines its roadways. Wildlife advocates have instead been forced to rely, as activists in the US so often must, on a hodgepodge of lawsuits and local lobbying.
The Wallis Annenberg Wildlife Crossing could well be transformative for local wildlife, and help keep Angelenos safer on the road for generations, but its most promising legacy may in fact be how it helped inspire a much broader movement and tranche of funding. The pilot program that P-22 helped inspire is now up for renewal, and seems poised to become permanent by the time that the Wallis Annenberg crossing opens in December.
Few wildlife corridors in the US will benefit from an über famous spokes-cat like P-22, a tireless local advocate like Pratt, or a roster of movie stars and philanthropists willing to pour time and money into building a new kind of bridge. Keeping local and federal governments on board with the projects may also be an uphill battle, given the national tenor. While many wildlife crossings have been embraced on a bipartisan basis, just a few months ago, Pratt received death threats after a smattering of right-wing media outlets assailed the Wallis Annenberg as a “butterfly bridge” to nowhere.

But if the US can successfully channel that cougar’s enduring star power into sustained support for a smart newish-to-us kind of infrastructure, one that’s been consistently shown to make a road much safer — and ultimately, cheaper! — for humans and animals alike, then maybe there’s a fair chance for the rest of us, and maybe this stubborn nation can get better at building things more like it.
“These things should just be part of transportation budgets and embedded in our infrastructure planning,” said Pratt, who is planning her first vacation in seven years once the bridge finally opens in December. “The ultimate goal is you don’t need someone like me.”
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