Mountain Lion Roadkill Tops 750 Yearly in California
A UC Davis report estimates vehicle collisions kill at least 750 mountain lions annually, about 18% of the state's population.
Updated on Nov. 10, 2026 in Wildlife
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A University of California Davis Road Ecology Center report estimates that at least 750 mountain lions die from vehicle collisions in California each year. The figure is a minimum, since reporting roadkill is not required and the data covers only state highways and major paved roads.
Why it matters
Mountain lions have large home ranges and move many miles per day, so they encounter numerous roads and are especially vulnerable to collisions. The losses equal roughly 18% of the state's mountain lion population, raising concerns about the species' long-term survival.
The 750-animal annual figure comes from compiled roadkill reports and is a minimum, since no requirement exists to report wildlife deaths. Data covers only state highways and major paved roads, so local and rural losses are not captured.
The players
University of California Davis Road Ecology Center
The research center at UC Davis that studies how roads affect wildlife and ecosystems, and that authored the report.
Caltrans
The California Department of Transportation, which manages the state highway system and its wildlife crossing structures.
The details
The report highlights Interstate 280 on the San Francisco Peninsula and Highway 101 in Marin County as among the highest-rate deadly collision sites around the Bay Area. It recommends metal mesh wildlife fencing, ideally at least 8 feet tall with outriggers, stretched between posts to keep animals off highways and channel them to existing passage structures. Caltrans manages at least 8,500 wildlife crossing structures, but most lack barrier fencing.
Timeline
Each year: at least 750 mountain lions die in vehicle collisions.
Tuesday, November 10, 2026: UC Davis report released.
2026: California Roadkill Hotspots Report scheduled for publication with full data.
Seasonal Patterns
The report extends UC Davis Road Ecology Center research on California roadkill, adding a statewide mountain lion mortality estimate and fencing recommendations. Its findings build on the center's documented focus on linking highway infrastructure to wildlife losses.
Drivers on Bay Area highways such as Interstate 280 and Highway 101 should watch for wildlife, especially at dawn and dusk. Reporting roadkill sightings helps build the data that agencies use to prioritize fencing and crossings.
The takeaway
Wildlife crossings only work when paired with fencing that guides animals to them. Fixing mountain lion roadkill depends on closing the gaps in existing infrastructure.
Further reading
For more on animal movement and road safety, explore Wildlife coverage across the state.
Source note: This article includes information reported by KRON4.
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