Highway 12 cuts through the heart of Sonoma Valley, a stretch of road lined with vineyards, oak woodlands and neighborhoods. For decades it has also been a deadly barrier for wildlife — blocking deer, mountain lions, bobcats and other animals from moving safely between the Mayacamas and Sonoma Mountain ranges.
The Sonoma Land Trust has launched Right of Passage, a long-term effort to reconnect those fragmented habitats and restore wildlife movement across the valley.
“Highway 12 is a significant barrier,” said Sonoma Land Trust Executive Director Eamon O’Byrne. “Animals are getting killed trying to cross, and the valley’s ecological health suffers when populations can’t move, feed and breed across the landscape.”
The project aims to identify, protect and enhance key wildlife corridors — natural pathways that allow species to migrate between the mountains. According to the Land Trust, the valley is one of the most important pinch points for wildlife in the Bay Area, yet it is also one of the most developed.
“Conservation science tells us that species need room to roam,” said Karen Gaffney, conservation director at Sonoma Land Trust. “When habitats are cut off by roads or development, we lose biodiversity and resilience. Right of Passage is about giving wildlife a fighting chance.”
To tackle the challenge, the Trust has partnered with Caltrans, California Department of Fish and Wildlife, and regional conservation groups. Efforts include studying roadkill hot spots, mapping animal tracks with motion-triggered cameras, and designing crossings — underpasses or overpasses — that could allow animals to cross Highway 12 safely.
Sonoma Land Trust has already secured conservation easements in the valley floor and protected lands linking up to Sugarloaf Ridge and Annadel State Parks. Still, the crossing at Highway 12 is considered the missing piece.
“It’s the bottleneck,” O’Byrne said. “We’ve done a lot to protect the hillsides, but if wildlife can’t get across the valley, those protections don’t add up to a healthy system.”
The push comes as California embraces large-scale connectivity planning. In 2022, Gov. Gavin Newsom signed a bill declaring the preservation of wildlife corridors a state priority. The Wallis Annenberg Wildlife Crossing, now under construction over the 101 in Los Angeles County, has become a model for projects like Right of Passage.
Local leaders stress that the project isn’t only about animals — it’s also about people. “When we maintain healthy wildlife populations, we also maintain healthy watersheds, forests and open spaces that benefit all of us,” Gaffney said.
Community involvement is key. Sonoma Land Trust has organized volunteer “road watch” programs to log wildlife sightings along Highway 12 and educational events to build support.
“It’s a generational project,” O’Byrne said. “We know this won’t be solved overnight. But by starting now, by working with our neighbors and agencies, we can make sure the Sonoma Valley remains a living, connected landscape for decades to come.”
For more information, visit www.sonomalandtrust.org.
