The young lion known as P-55 is only the fourth documented successful crossing of the 101 Freeway since park rangers began studying local lions 15 years ago, in 2002. During that time, 17 lions were killed trying to cross the freeway. Early this year, a lioness was killed on the freeway, and in the following weeks, her kittens met the same fate.



The success of P-55 will have a major impact on Southern California's mountain lion population because hemmed in lion populations tend to inbreed.



According to the National Park Service, "P-55, a subadult male who was recently collared in the western end of the Santa Monica Mountains, crossed the artery near Thousand Oaks last week soon after he was caught on video in a Newbury Park backyard."

P-55 didn't stop with the 101 Freeway either. He's since crossed Highway 23 and the 118 Freeway and is roaming the Santa Susana Mountains. His freeway fearlessness is rare.



"The overwhelming pattern we've observed through GPS tracking is lions coming up to the edge of a freeway and turning around," said Seth Riley, a wildlife ecologist at Santa Monica Mountains National Recreation Area. "So it's really interesting to see another lion get across. As a whole, however, lions face significant challenges moving around the fragmented landscape in and around the Santa Monica Mountains, especially across larger roads and through intensely developed areas."



The 101 Freeway is one of the biggest obstacles for lions born in Santa Monica Mountains, where it's unusual for male cubs to survive long enough to carve out their own territory. Male lions will kill one another for territory. The lack of genetic diversity is a serious threat to the survival of mountain lions in the Santa Monica Mountains, according to a study by researchers at UCLA. They found that without increased connectivity, especially animals moving in from the north, the lions face an increased the chance of extinction.



So far, P-55 has beaten the odds — not only by surviving his freeway crossing, but by simply surviving at all.



"The lack of connectivity also limits dispersal of young male mountain lions, who at about 1.5 years old leave their mother to find their own territory. Without the ability to easily leave the Santa Monica Mountains, it leaves young males trapped in another male's territory, potentially increasing the chances of conflict," according to the National park Service. "It is very rare for a male mountain lion born in the Santa Monica Mountains to survive past the age of two, based on the animals studied so far."