We already knew that the mountain lions of the Santa Monica Mountains were inbred and isolated, but we haven't known how long the local population might survive under those conditions. A new study predicts they could be extinct in 50 years.

Hemmed in by the ocean, 101 and 405 freeways, and urban development, the mountain lions are isolated from natural habitats. KPCC says they're in a "genetic prison" that forces them to inbreed. John Benson, one of the study's authors and a wildlife ecologist with the La Kretz Center for California Conservation Science at UCLA, tells KPCC that inbreeding can progress to such an extent that the offspring’s chances of survival are low, and their ability to reproduce drops. In a small population of mountain lions, that could spell extinction in a short amount of time.

"Fifty-plus years ago when the 101 Freeway was built, no one was thinking about wildlife connectivity," Seth Riley, a wildlife ecologist for the National Park Service and one of the study's authors, said.

There is some good news: The study says we can keep the mountain lions from disappearing with a wildlife crossing over the 101.

That crossing would allow animals to traverse the highway successfully, meaning that other mountain lions could come into the habitat and the Santa Monica mountain lions could go out. "If we were even able to get one new mountain lion every two years or, even every four years, it would considerably lower extinction probability," Benson told SCPR.

The $60-million crossing, which would bridge the 101 Freeway at Calabasas’s Liberty Canyon, is at the end of the design phase right now. Once the crossing is completed, it would help connect predators in the Santa Monica Mountains to those in the Santa Susana Mountains and in the Simi Hills, says KPCC. The privately funded Caltrans project has raised $1.2 million so far, but will need to hit $10 million by early 2017 to stay on target.