Puma Profiles: P-61, the First Collared Mountain Lion to Cross the 405 Freeway

P-61 — male, first captured in October 2017 — was one of the mountain lions tracked by the National Park Service in the Santa Monica Mountains.

P-61. NPS.

A first — and a last crossing

On July 19, 2019, between 2 and 4 a.m., P-61 crossed the 405 Freeway, the first GPS-collared mountain lion in the study to make it across the ten-lane highway. Near where he likely crossed, P-18 had been killed by a vehicle in 2011, and an uncollared lion in 2009.

Two months later, at about 4 a.m. on September 7, 2019, P-61 was struck and killed on the 405 in the Sepulveda Pass. His last GPS point placed him between Bel Air Crest Road and the Sepulveda Boulevard underpass.

The best-known lion to cross the 405 is P-22, but he wore no collar then, so little is known of his journey. DNA shows he was born in the Santa Monica Mountains, so he must have crossed both the 405 and the 101 to reach Griffith Park, where he had lived for more than seven years. Researchers also know of an uncollared male lion that seems to live in the same small area between the 405 and the 101; surveillance-camera images of it — if it is the same animal — go back about five years.

His life

P-61 was captured at the eastern end of the Santa Monica Mountains in October 2017, apparently less than 2 years old. About a month earlier, biologists had found the remains of P-27, the adult male who had ruled that end of the mountains since at least 2013; his GPS collar had failed and he had been dead for at least a month, so the cause of death is unknown. P-61 weighed 97 pounds when first captured and 119 pounds at his last capture.

Sources

• National Park Service, Santa Monica Mountains National Recreation Area, "Puma Profiles: P-61." https://www.nps.gov/articles/000/puma-profiles-p-61.htm
• NPS news release on P-61's crossing: https://www.nps.gov/samo/learn/news/mountain-lion-crosses-405-freeway.htm