San Benito US 101 Wildlife Crossing

Advancing a landmark wildlife overcrossing between two major mountain ranges

San Benito County, California

US Highway 101 separates two of California’s most biologically important mountain ranges, limiting wildlife movement between the Santa Cruz Mountains and the Gabilan Range.

Near Rocks Road, this heavily traveled corridor has become a persistent barrier for mountain lions, deer, bobcats, and other species moving between protected habitats.

Rock Design Associates is supporting the development of a large wildlife overcrossing designed to restore movement across US 101 and connect thousands of acres of habitat with the permanently protected Rocks Ranch.

Working with the Land Trust of Santa Cruz County, Wildlife Conservation Network, and Caltrans District 5, RDA has provided technical review, site evaluations, and ecological guidance as the project advances into the PS&E phase.

Drawing on experience from wildlife crossing projects across the West, RDA is helping shape infrastructure that responds to both ecological and transportation needs.

The project represents an important opportunity to improve roadway safety, strengthen habitat connectivity, and support long-term movement between two major mountain systems.

Designing for long-term connectivity

A successful wildlife crossing must do more than span a roadway. Its location, scale, approaches, surrounding habitat, and relationship to protected lands all influence whether wildlife will use it effectively over time.

RDA’s technical and ecological guidance helps ensure that design decisions remain grounded in how animals move through the broader landscape while also meeting the requirements of a major transportation project.

As one of California’s most significant wildlife crossing initiatives, the San Benito US 101 project represents a long-term investment in the resilience of the state’s natural landscapes.

More than a crossing

The Wallis Annenberg Wildlife Crossing represents what becomes possible when science, design, engineering, advocacy, and public support move toward a shared goal. It restores a vital connection across one of Southern California’s most significant barriers while creating a model for how infrastructure can respond more thoughtfully to the natural systems around it.

For Rock Design Associates, the project reflects a long-term commitment to collaboration, ecological understanding, and design that serves both people and place. More than a passage over a freeway, the crossing is a lasting investment in the resilience of the Santa Monica Mountains and the wildlife communities that depend on them.