MALIBU—P-23, a female mountain lion that has been researched and observed by the National Park Service for years, was found dead on the side of a road on earlier this week.

P-23’s body was found beside Malibu Canyon Road and, according to staff from the National Park Service, it appeared that she had been killed by a car running her over. When they found the mountain lion’s body, the staff determined that she had been run over earlier this week.

P-23 had three litters of kittens. One of those litters included P-54, who is the latest mountain lion found and tagged in the Santa Monica Mountains. P-23 was just one of the many mountain lions currently being tracked by the National Park Service. She was, like many of the others, the result of inbreeding. P-23’s father, P-12, was also her grandfather. She mated with P-12 as well.

The Southern California mountain lion population is at risk of extinction, with researchers from UCLA, the National Park Service, UC Davis and Utah State University indicating the species have a 99.7 percent of being wiped out in the next 50 years. The inbreeding is a large part of the problem; as infrastructure has developed around the Santa Monica Mountains, the lions have found themselves surrounded on all sides by highways.

“P-23’s tragic death is a reminder that wildlife corridors and open space are critical to the survival of these magnificent cats. California needs to stop funneling money into more highway projects when our existing road networks don’t include crossings to protect mountain lions and other key members of our ecosystems.” J. P. Rose, a staff attorney at the Center for Biological Diversity, said in a statement.

The highways act as barriers, containing the population, where mountain lions from other regions of Southern California cannot enter and mate, leading to inbreeding. Inbreeding can lead to problems including mutations, decreased genetic variety and diseases.

P-23 is the 18th mountain lion found dead since the National Park Service began monitoring them back in 2002. She was brought into the spotlight in 2013, when a picture of her on top of a dead deer on the side of the road circulated through the internet.