The grim discovery was made shortly before 5 a.m. in the slow lane on the southbound side of the freeway, near Liberty Canyon Road, according to a CHP incident log.
The deceased animal's body was moved to the right shoulder, and California Department of Fish and Wildlife personnel were summoned to the scene, the Highway Patrol said. Whether the uncollared mountain lion had been struck by a vehicle was not immediately confirmed.
Late last month, surveillance video captured a large cougar prowling the backyard of a nearby home in Agoura Hills.
"I was 50% 'This is the most beautiful animal I've ever seen in my life' and 50% terrified," resident Peggy McClintick told ABC7 on May 29. It was unclear if the same mountain lion was found on the 101 Freeway Saturday.
Mountain lion in backyard makes beautiful, frightening sight for Agoura Hills couple
After weeks of overnight lane closures, the wildlife crossing project reached a construction milestone last month when its final girder was installed.
Installation of the girders began on April 15, starting on the southbound side of the freeway. At the beginning of May, the work shifted to the northbound side.
Construction on the overpass began in 2022, and it is expected to be completed by late 2025 or early 2026.