It sounds like the plot of a Disney movie: a mountain lion prevented from finding a mate because he's trapped by L.A. freeways becomes famous and inspires the construction of the world's largest wildlife overpass.
But it really happened.
"He was surviving in a space much, much smaller than any male mountain lion ever had — eight square miles," explained Beth Pratt, the California Director of the National Wildlife Federation. "The average male mountain lion territory is 150 miles."
The cougar, named P-22, became a celebrity among Hollywood stars who would sometimes spot him as he roamed near the neighborhoods near Los Angeles' Griffith Park.
"A mountain lion lived in L.A. and people didn't fear him," said Pratt, who has memorialized P-22 on her arm with a tattoo. "They saw him as a neighbor; they'd be eating dinner and he'd walk by their dining room at night and they'd share a photo and be like: 'Hey, P-22 visited me.' "
One of her career highlights was getting an email from actor Alan Ruck — from HBO's "Succession" and Pratt's favorite film, "Ferris Bueller's Day Off" — saying he spotted P-22 from the deck of his Hollywood Hills home.
Because of P-22's popularity, people wanted to help the mountain lion -- and others like him -- roam the areas beyond Los Angeles' bustling six-lane 101 Freeway. The idea of a wildlife overpass was garnering interest, but funding it was another issue.
So Pratt, who is most comfortable outdoors in casual clothes and hiking boots, found herself in swanky Bel Air mansions, pleading for endowments.
Donations poured in from celebrities including Leonardo DiCaprio, Rainn Wilson, Barbra Streisand and David Crosby — but also from Watts residents in South Los Angeles.
Residents of Watts see P-22 as "a social justice hero," Pratt explained.
"He's someone who was also impacted by the injustice of putting freeways through communities," she said. "Whether you're [living in] Beverly Hills, whether you're [living in] Watts, we all come together over wildlife."
Finding the right spot
Some 300,000 to 400,000 cars a day will pass underneath the Wallis Annenberg Wildlife Overpass when it opens in two years.
The crossing includes specially designed sound walls, along with natural sound barriers of tall trees and lush plantings. Everything is designed to filter out the noise of the freeway, since most animals get frightened and turn around if it's too noisy.
Engineers are also taking into account animals' fear of bright lights.
"All the lights of those headlights are a deterrent to wildlife," Pratt explained. "We're actually designing light barriers — not just on the crossing but in the approach — so they won't get scared and turn around, which is what happens."
The wildlife crossing is a public-private project, spearheaded by the National Wildlife Federation along with California's transportation department. About half of the $100 million cost was funded by private donations, including $26 million from philanthropist Wallis Annenberg, whose contribution was instrumental in propelling the project forward.
For 20 years, the National Park Service researched the exact spot where the freeway overpass should go. They looked for the busiest part of the highway — an area they know most animals wouldn't cross without this overpass.
"You couldn't pay me a million bucks to run across that road," Pratt said. "This freeway is so big and loud and noisy and too many lights ... animals don't even try."
It's not the first wildlife crossing
Wildlife crossings were first constructed in France in the 1950's. They're in use across Europe, and are especially popular in the Netherlands.
Wildlife corridors have even worked with animals not considered particularly intelligent.
When vehicle hits were blamed for much of the decline in the koala population in Queensland, Australia, engineers created a series of tunnels and bridges to help them avoid busy roadways.
But Australian wildlife officials predicted koalas — notorious for chilling out in trees, stoned on eucalyptus — wouldn't figure them out. So those same wildlife officials were pleasantly surprised when the koalas took less than three weeks to start regularly using them.
In Canada, a series of wildlife bridges and underpasses at Banff National Park has proven wildly successful. The wildlife corridors pass over and under the giant Trans-Canada Highway, which cuts the park in half.
Scores of big animals utilize the system, including grizzly bears, black bears, moose, elk and cougars. The system is credited with helping grizzlies sustain their population by providing access to mates on both sides of the park.
And that's exactly what needs to happen at the Wallis Annenberg Wildlife Overpass, where the freeway bisects the local cougar habitat.
One to two million big animals die on US roads every year from vehicle accidents, according to the Federal Highway Administration. Pratt says that number is "way under-counted" since those are only the crashes that are actually reported.
"And if you add in the little guys — frogs and butterflies — we're talking in the billions," said Pratt.
She believes the crossings have widespread support: "No matter what political affiliation you are, where you live, it doesn't matter. Most people love wildlife and don't like seeing it get hit."
There are also economic benefits, according to Pratt, since they are infrastructure projects that come with jobs and have human safety benefits.
It's an environmental problem with a simple, proven solution, Pratt says, and the only thing that stands in the way of building them is money.
"There's no bad guy. We don't have to figure out the technology. We just need the funding."
Rewilding an L.A. freeway
Besides its massive scope, the Wallis Annenberg Wildlife Crossing is different from other wildlife overpass systems across the world in that it will host a whole ecosystem on top of it.
A plant nursery nestled under an overpass is growing native, fire-resistant plants that will eventually cover the crossing.
"We've been collecting seeds for years now to match the surrounding ecosystem, and that's important with climate — both wildlife and plants need options," according to Pratt.
Invasive, fire-fueling plants — including the ubiquitous black mustard plant — will be removed from the area. The nearby utility poles had to be moved to accommodate the crossing, so those will now be placed underground, which will also help with fire resistance.
"Not only are you going to have wildlife like mountain lions and bobcats crossing it, you're going to have monarch butterflies laying their eggs on milkweed on top of it, you're going to have western fence lizards living on top of it," Pratt said.
"Part of this project is we are going to be restoring the landscape, not just on the crossing, but around it, back to what it should be. So that's going to help with a lot of things, as well as fire risk."
P-22 won't be around to use the wildlife crossing that he helped inspire. In December 2022, just a few months after the National Wildlife Federation and California's transportation department broke ground on the bridge, the cougar died.
Although his death was heartbreaking, Pratt said he actually lived a long life for a mountain lion.
"But more than that, he used his celebrity for good. I call him the 'ultimate cougar celebrity influencer.'"
His story, she said, ensured a future for other mountain lions in the region.
"And we owe him a debt of gratitude. He has inspired the building of the Wallis Annenberg Wildlife Crossing. We would not have it without him."