California Connectivity

Wildlife crossings are supported by nearly everyone. They save human and animal lives. While most people have heard of the world’s largest crossing, the Wallis Annenberg, in Southern California, or the first I-5 overpass just 2 miles north of the border in Oregon, multiple corridors are being planned throughout California, including a few in our backyard. With over 180 threatened and endangered animal species, more than any other state, and over 15,000 miles of highway system, the passing of the Room to Roam Act and the Safe Roads and Wildlife Protection Act is setting the ground for wildlife connectivity. Proposition 4 is also a boon, which devoted 180 million dollars to the cause. 

CDFW Wildlife Movement Barriers

As hot spot roadkill areas have been documented on virtually every route in the state, Caltrans and the California Department of Fish and Wildlife (CDFW) have been busy studying, prioritizing, and planning. The projects could be in the form of overpasses, underpasses, culverts, or other infrastructure, which can reduce wildlife-vehicle collisions by up to 98%. Megafauna, like elk, wolves, bears and mountain lions, often take the limelight but connectivity is also essential for smaller animals, which are a majority of our threatened species, such as Red and Yellow-legged frogs, Sierra Nevada red fox, Coho and Chinook salmon, Giant garter snakes, multiple salamanders and more.

According to the Caltrans Wildlife Connectivity Website and the 2024 Report, the first baseline inventory of aquatic and terrestrial barriers in the state, 31 funded remediation locations are being actively developed, 37 priority areas are in planning, and another 75 priority areas that will require more funding. Stone Lagoon on 101 and Essex Gulch, just outside of Arcata on 299, are at the top of the list. The next north state priorities include: Palmer Creek on 101 near the Eel River outside of Fortuna; May Creek off 101 just south of Prairie Creek Redwoods State Park, and Willow Creek off 299 a few miles west of the town of Willow Creek.

Being charged with the responsibility of all of California’s wildlife, CDFW is a critical partner in helping to determine priority wildlife crossing locations. The Wildlife Conservation Board, which oversees Prop 4 funding, uses this as a primary source of information when determining grant funding. An additional layer to the priority locations map is the Areas of Conservation Emphasis (ACEs) data, which highlights the state's incredible biodiversity and is often underutilized and not fully appreciated. 

The concept of habitat connectivity continues to evolve but has long been recognized as essential for species survival, which is even more crucial now given the climate and biodiversity emergency. The 2010 California Essential Habitat Connectivity Project laid the foundation, and now, with the new legislation, even city and county planning must update their conservation element in local land use plans, by 2028, to identify and incorporate habitat connectivity, determine development impacts and to avoid and mitigate impacts to the maximum extent possible.

Images from Caltrans Report

Championed by many, support for wildlife crossings is widespread and worldwide. There is an exorbitant amount of information, data, and science being collected on the need for connectivity and the demise of wildlife from roads. Books have been written on the subject. There are many people, organizations, and partnerships working to make corridors a reality. We thank our friends at the Center for Biological Diversity and the Wildlands Network, who were instrumental in passing our states’ connectivity legislation.

Wildlife crossings aren't just bridges for animals—they're lifelines, ensuring that our furry, feathered, frog, fish, and insect friends can traverse safely, while keeping life-sustaining ecosystem functions from going off track. As California builds this network, it signals a growing recognition of the need to balance development with preserving irreplaceable biodiversity for future generations. The journey toward a more connected, wildlife-friendly state is far from over, but the progress so far is an inspiration for the road ahead.