Beau Bridges: For thousands of years, mountain lions roamed North America's mountains and valleys.

But within a few hundred years of Europeans arriving, humans decimated cougars from their home territories.

Today, only 15 or 16 states in the US have established cougar populations.

California boasts one of America's largest mountain lion populations at somewhere between 3,000 and 4,000 individuals.

Although more than 39 million people live in California, most of its residents live within dense urban centers, giving plenty of space for cougars to hunt and breed in virtually uninhabited territory.

Los Angeles is an exception with perhaps as many as two dozen mountain lions living within the greater LA region.

Of all global major cities, only Mumbai, India, has a reputation for being home to such a large number of big cats.

Robert Martinez: Yeah, when most people think of Los Angeles, they think of, like, you know, the big suburbs, the high rises, Hollywood, and just suburbia, nothing but a concrete jungle, but yet if you just go ten minutes beyond that, you're right there in the middle of nature, like that's P-22 exemplified for ten years in the Hollywood Hills.

Go a little further, it gets even better.

You see lions flourishing, bears flourishing.

It's always been really cool to see how the wildlife still thrive and, when areas are undisturbed, that's when the magic really happens.

It's so special to know bears and lions are thriving in some of the healthiest parts of Los Angeles and all throughout the valley.

Where I'm at, I'm only like 5 miles away from civilization, you know, residential areas, schools, strip malls, so to go only ten minutes further into the mountains and see what takes place when there's no people around, it's incredible to see.

Robert: The mountain lion is the apex predator of the Angeles National Forest, top of the food chain.

They see us, yet we very rarely see them, which is why they get the nickname Ghost Cats.

So that's always intrigued me, like, knowing they're like this ghostly cat that you never get to see.

So with technology and for me discovering trail cameras has allowed me to observe their behavior, capture images of them, hearing sounds I never knew they even made, seeing behavior I didn't know they would ever exhibit in front of my own camera.

So, getting a glimpse of a mountain lion for anybody who loves doing what I do, it's very rare and special to see.

[shrieking] Beau Bridges: In Los Angeles, one lion in particular designated as P-22 lived in Griffith Park for nearly ten years.

Photographer Steve Winter's photo of that cougar near the Hollywood sign became a worldwide viral sensation.

P-22's recent death caused by a variety of human-related injuries, has now drawn attention to the need for more protection for cougars and other wildlife in the region.

Gavin Newsom: P-22 was certainly an icon in California and obviously represented so much more, you know, who we are, who we were, and who we can be, inspired us to do better, remarkable, right?

A mountain lion, inspired us to do better and to help us work with nature rather than against it simply by carrying on in his own little island of wilderness in the heart of Los Angeles and captivated people all around the globe.

Beau Bridges: One of the key factors causing mountain lion fatalities is the LA freeway system.

Millions of cars travel the high-speed roadways each day, often crossing through hills and mountains that are natural homes to cougars and other wildlife.

Fortunately, all this attention has helped bring about the building of the world's largest highway wildlife crossing, a public-private partnership that has leveraged expert organizations and sponsors nationally and internationally.

Named after major donor, the Wallis Annenberg Foundation, and supported by Governor Gavin Newsom, the Crossing core team includes Caltrans, the National Park Service, the Santa Monica Mountains Conservancy, plus the National Wildlife Federation.

Beth Pratt: Freeways isolate habitat.

And what we found here in Los Angeles, what the scientists found, was that wasn't just a "can't cross the road" problem.

Mountain lions and other wildlife were genetically collapsing to the point of inbreeding themselves out of existence.

They needed connected landscapes, and that's what the Wallis Annenberg Wildlife Crossing did, preserve not just the future for mountain lions, but the future for all wildlife in the Santa Monica Mountains.

Beau Bridges: Meanwhile, in another bright spot for mountain lions, a local part-time photographer, Robert Martinez, has quietly gone about documenting and celebrating cougars and other wildlife far from the freeway system.

♪♪♪ Robert: We're in the northeast region of the Angeles National Forest, and we're gonna drive up this mountain road and then drop back down into this canyon over here, the remote and undisturbed canyon where I never see human activity.

Nothing but wildlife, bears, mountain lions, foxes, bobcats, it's got it all.

So we're heading to a remote and undisturbed creek.

I don't disclose locations like names, but it's a very, very healthy habitat with plenty of water sources that stay full all throughout the year, especially after this year's rainfall, even more water than last year, but I've been lucky to observe in this creek that the water sources never dry up.

There's always water for these animals, so we're heading there right now.

It's one of the places, Wilford the bear likes to frequent, a couple of different male mountain lions.

In July, I saw a mountain lion family.

One quick clip I haven't seen them since, so I'm really hoping to get a glimpse of them again before they get too big and move on.

This road actually wasn't drivable.

They did some grading on it in February.

And now it's drivable.

I used to walk this road.

But now that it's accessible, I use it to get to the creek.

Saves me about an hour of my time being out in the forest on those busy, busy days.

And I always drive slow on this dirt road looking for animal tracks that might stand out because all the animals use this road.

It's a private road, it's hardly anybody ever driving on it, so all the animals feel free to walk on it when they need to get somewhere in a hurry.

All right.

So I'm mostly obsessed with mountain lions.

That's kind of how this whole passion started.

I've been intrigued by them since I was about 8 years old.

I was always intrigued that they were just there but seldom seen, which is why they call them ghost cats.

So flash forward to 2011, mountain lions were on my mind.

I was taking some deep hikes in the forest, stumbled upon some mountain lion tracks I wasn't even looking for.

And then in four or five months I discovered what trail cameras were.

And then set one out there, back where I first saw those tracks.

After a few weeks, I got my first lion video, like three seconds of a lion in broad daylight, walking towards my camera and breathing, and after that it just triggered me to want to see more.

Beau Bridges: For the last ten years, Robert has gone from a novice struggling to capture local animal scenes to really understanding signs of wildlife, their travel routes, and likely places to find them emerging from the forest.

Robert: First signs of bear activity, bear scat.

It's always large and it has signs of berries in there.

Got some bear scat there, there, and over there.

We'll see a lot of that along the trail.

This place is used heavily by the bears, so it's not surprising to see that.

Hopefully, we'll see some stomp marks too left by their big paws.

Beau Bridges: He continues en route to check his trail cam.

Robert: Well, sometimes you, besides being on the canyon floor or the creek floor like down here, you wanna get some of the higher areas like the ridgeline right up here.

So I know the lions travel up there sometimes because I found lion scat and signs of lion prints.

So yeah, the lions use the creek down here and the ridgeline up there.

And I plan on returning up there again with my new camera in the next few weeks.

♪♪♪ ♪♪♪ Robert: So as you can see, this creek is really healthy with pretty much countless water sources all throughout.

So even just first entering the creek, you can put a camera here and probably get an animal stopping by to drink, to cross over or whatever, maybe even bathe, but I want to choose a different part where there's like a nice choke point where the canyon has a pathway that crosses the water.

This is more just like a little corner area, so there's so many pools of water just like this, but also I look for signs of mountain lion activity, like lion scrapes.

Endless possibilities in this creek, endless.

[water rippling] Robert: So my first visit in this creek, two years ago, I knew I was on the lion's path.

And then when I got stopped, right here at the sight of lion scat on the ground, I knew I was really on the right path, and I did have a camera on hand with me, and I placed my first camera over there on that tree.

I would say I got about two or three different lions in that year's time.

So when the lion feasts on a deer for about three to four days, the first scat is usually black and very putrid because they're eating all the organs and everything rich in blood, and towards the end, they're getting like, you know, some skin and some bones, a little bit of deer hair.

That's what you see right here, probably one of the lion's last scats with signs of the deer still in it.

Beau Bridges: Over the years, Robert's trail cameras have not only revealed cougars but many secretive creatures like this baby bobcat.

Or a pair of golden eagles.

An assortment of wildlife on a mission.

Old regulars.

Plus this curious bobcat.

Then some very frisky bears, feeling affectionate in their mountain hot tub.

♪♪♪ ♪♪♪ And even more remarkable, wildlife behavior rarely if ever photographed in a completely natural setting.

Robert: It was a easy spot to enter into the creek, and there was a water source right there.

It would dry up throughout the end of summer and then fill up again in the winter.

So my camera was there for about a year and then one of these random camera checks, my camera turns on, there's a bobcat coming out from behind my camera.

And then he's looking at this pile of branches and he's looking for something and all of a sudden I can hear the rattle sound and he's trying to coax this rattlesnake out of the branches.

Next thing you know, a fight ensues for the next two minutes.

And that was by far the most nerve-wracking, nail-biting footage I've ever watched right there next to my camera.

Can the rattlesnake win and bite this bobcat and kill the bobcat?

I did not know, so it was like watching this championship fight live for the first time.

I was nervous.

♪♪♪ Robert: And then rewatching it, you know, now, the bobcat looks in control the whole time.

♪♪♪ It just shows you how in control and fast the reflexes are of a bobcat, really intriguing scene to see and you hear the birds chirping from above, you hear the rattling stop abruptly when it crunches the head of the rattlesnake.

It's a very, very dramatic and detailed video.

♪♪♪ Beau Bridges: Robert's trek to check his trail cam continues.

Robert: The reason this pathway is so popular for the lions and the bears is because the close proximity to the creek.

The water is only a feet away, right there.

So all along this pathway they have access to water, whether it's a drink or bathe in it.

Robert: Bear scat left by Wilford.

Let's see if we got him on camera in the last week.

Let's see if we got any new footage of Wilford or the male mountain lion.

They both have been here in the last few weeks.

Let's see if we got any recent visits.

All right, that's just me leaving the camera.

Days later, there's a female bear.

It looks like the mom bear.

All right, minutes later, one cub passes by.

Several more minutes later, the other cub passes by.

Oh, after that cub left, interesting, less than three hours later at 3 in the afternoon, this large male mountain lion passes by, who I've seen before.

I recognized him right away because of his shorter tail, and he's got a slash on the side of each ear.

I could tell right away based on the muscle mass, the size of the head.

It's a male lion.

And this lion, in particular, has a shorter tail than the average lion, which maybe he was born with that short tail or got into a fight.

This is a very popular area with lions, bears, bobcats, foxes, deer.

Pretty much every animal that lives in the forest will pass by here sometime throughout the year.

Beau Bridges: It's the sheer volume of animals moving throughout the Los Angeles region that makes the construction of highway connectors for wildlife so crucial.

It may mean fencing, culvert improvements, or the building of underpasses or overpasses like the Wallis Annenberg Highway Crossing.

In virtually every location from Canada's Banff National Park to Montana, these crossings have saved the lives of animals and potentially many people.

And it was the death of a famous lone cougar, P-22, in part due to a vehicle collision that further drew the public's attention to this issue and was noticed by governor of the state.

Gavin: Something connects me to his legacy is my legacy of my own dad, my father, Judge Newsom, who was a long-time wildlife activist and he was founder of both the Wildlife Conservancy and the--one of the founders of the Mountain Lion Fund who helped instill in me a great respect for mountain lions.

I remember going as a child on many different occasions with my dad where we took photos of mountain lions and helped collar them and replace collars.

We always had these extraordinary experiences in nature, appreciating, respecting, and revering these magnificent creatures.

Beau Bridges: Recently, the state passed more than one bill banning the use of rat poisons, a leading cause of death in cougars, hawks, coyotes, and other predators that feed on rodents.

[shrieks] Robert: All right, I gotta pause it for a minute.

So this video is probably my favorite video of the year, absolutely.

This is the kind of clip I dream about.

One of these beautiful lions right in front of my camera.

This little Bushnell Aggressor camera capturing this.

[shrieking] Robert: So a lot of times you can't distinguish one mountain lion from another.

Every once in a while something stands out.

So in 2013, I started seeing this female cougar, very well fed and healthy, but I noticed she wouldn't put pressure on her right rear leg.

And right away when people saw that and I shared the videos, they kind of thought like, "Oh, her days are probably numbered now, you know, an apex predator with a bad leg.

How is she going to survive?"

Yet I've been following her for ten years and I've seen her with three different litters of kittens.

So flash forward, like, four months later into February of 2018, I had my camera waiting on the ridgeline where I've seen her before and all of a sudden before the sun goes down, at around 6 p.m. she shows up with her three yearlings.

My video camera triggers.

She chirps to them to kind of come up the ridgeline like it's okay, it's safe.

And then my DSLR starts flashing and I captured a couple of iconic images of that family.

So that was one of my most rewarding moments because I kind of dreamt about it for about four months.

Robert: Only a few months after I got that iconic image of the four lions at sunset, the US Forest Service reached out to me about using my picture and another one from that series for an ad campaign at LAX Airport, one of the busiest places in the world.

So, of course, I said yes, it was an honor, and they gave me credit and all that.

And at the same time, they gave me access to some closed off areas of the forest to be a storyteller and share my work with the public and the Forest Service.

And ever since then, for the last five years, it's been a dream come true going into unmarked territory where people aren't a factor and I could see wildlife thriving without any disturbance.

Beau Bridges: This access has allowed Robert to capture some truly remarkable scenes, such as experiencing the bond between a mother bear and her cubs in which the cubs master both the art of wrestling and tree climbing to escape danger, with a dash of discipline thrown in to maintain order.

♪♪♪ Robert: People like to comment a lot about, you know, "Watch out for the mom bear and the cubs, you don't want to run into them," but I've had those encounters, you know, probably half a dozen times, and each time the mom bear and the cubs just want to get away.

She gets her cubs to follow her along and go up into a tree or just go down into the--to the creek and get away from me.

So what I've learned is bears do not want to mess with people, they just want their space.

That's all they want.

♪♪♪ ♪♪♪ Robert: So what I wanna show people, is that these animals have it really well in this healthy undisturbed habitat.

They have food sources throughout the year, water sources, so don't feel bad for them and leave out your dishes of water.

They don't need your help, they know what they're doing.

The Wallis Annenberg Bridge is just a start for us giving back to the animals that we've taken so much away from: their space, their connectivity.

Mountain lions need to spread the gene pool or you have inbreeding, a lot of fighting, you know, large males killing kittens because they're fighting over space or mates.

So we need this connectivity after all these years of damage we've done.

So it's just a start.

We need so many more bridges to let the lions spread, let the bears, the deer cross the freeway.

Beau Bridges: And the issue of animals in conflict with humans is not limited to California, of course.

Throughout the planet, wildlife is finding itself in a head-to-head battle for space in shrinking forest habitats and growing agricultural and urban centers.

Awareness and respect for wildlife is the key.

Robert: In the last couple of years I've been showing people what can really happen when you leave areas undisturbed, spreading awareness, showing people what really lives in the mountains and what we want to protect for future generations, including my daughter.

Robert: Yeah, it was nothing more than a hobby that's turned into this whole advocacy, educational, hopefully inspiring other people to get out there.

What I do this for is just to see what the wildlife might do next in front of my camera and to learn more along with everybody else and see what's the next wild moment that might happen, whether it's a skunk chasing a mountain lion or, you know, a bobcat killing a rattlesnake.

Those kind of things that would drive me to, like, what can happen next, you know, a lion walking by with three new kittens, that kind of thing, or a bobcat with a little baby bobcat kitten.

Those kind of things keep me, like, inspired after all these years to keep going at it.

It's just all for the love, the passion, and just what else can I see?

I did not know I'd even go this far seeing what I get to see, so it's constantly, what can I see next?

What else can I see?

♪♪♪ [elephant trumpeting] ...