Sadly, experts now believe the animal was killed over the summer in a car crash on the 405 Freeway near the Getty Center.
"It did bring us a lot of hope," said Beth Pratt with the National Wildlife Federation. "It brought us a lot of hope that 'OK, Griffith Park can be habitat for these cats. They're trying.'"
At the time, Pratt said it wasn't known the mountain lion was the same one spotted in Griffith Park.
"It broke my heart even a little more when the scientists put it together that this is probably what was going to be P-122," Pratt said.
The most famous of these mountain lions was P-22, who lived in Griffith Park for a decade.
It's difficult for mountain lions to survive in an urban area. The National Park Service has tracked a number of these cats as they move in and around the Santa Monica Mountains.
"The number one threat to wildlife worldwide, especially in times of climate disruption and biodiversity collapse is loss of habitat," Pratt said. "We keep taking away more and more of their space."
To protect the animals, a wildlife crossing is being built on the 101 Freeway near Agoura Hills so they can safely traverse the mountains.
"P-22 did inspire the Wallace Annenberg Wildlife Crossing," Pratt said. "He showed people - it wasn't just like a scientific paper - he showed people what it meant to be a wild animal trapped by freeways."
Pratt said the 101 Freeway crossing is just the beginning. She said there are plans to build other wildlife crossings over the 5 Freeway and 134 Freeway near Griffith Park. She hopes that will allow mountain lions to move around safely.