As Colorado continues to navigate the complexities of a changing landscape, the push and pull between human expansion and wildlife preservation has never been more prominent. For residents driving along the Front Range or navigating the mountain corridors, the question often arises: how do we maintain our sprawling transportation networks while ensuring that the state’s native species have the space and connectivity they need to thrive? The answer, increasingly, lies in a multidisciplinary approach that moves beyond simple land management to focus on proactive, heavily engineered solutions. This is the science of safe passage.

At its core, this approach is about bridging the most dangerous intersections of the human-animal interface: our highways. It involves utilizing migration data and structural engineering to eliminate conflicts before they occur. Just up the road from Monument, near Larkspur, this coexistence recently took shape as a massive feat of concrete and earth. The I-25 Greenland Wildlife Overpass, which recently completed construction, spans six lanes of interstate traffic. Covering nearly an acre of ground, it stands as the largest structure over a major roadway built exclusively for wildlife in North America.

By taking advantage of these dedicated, vegetated crossings, large game animals like elk and mule deer can safely navigate between the vast protected open spaces of Douglas County and the Pike National Forest. Biologists have long understood that elk, in particular, avoid dark, enclosed tunnels, making these wide-open, naturally landscaped overpasses essential for their movement. Prior to the mitigation system being built in this corridor, there was an average of one wildlife-vehicle crash a day during peak migration seasons. The science of safe passage proves that when we build to accommodate the specific behavioral needs of these animals, the results are immediate. Similar structures previously built on Colorado’s Highway 9 near Kremmling reduced wildlife collisions by an astonishing ninety percent.

While the initial price tag for these structures is significant, the economics heavily favor construction. The Greenland overpass cost roughly fifteen million dollars and was completed ahead of schedule and on budget. When weighed against the ongoing economic toll of inaction, the investment quickly pays for itself. Collisions between vehicles and animals in Colorado cost an estimated three hundred and thirteen million dollars annually in property damage, emergency response, and medical expenses. A single crossing structure with a seventy-year lifespan in a high-traffic area will ultimately save taxpayers and drivers tens of millions of dollars, all while preserving the lives of motorists and the state’s big game populations.

Conservation funding is the backbone of these efforts. Recent state investments, bolstered by federal grants from the Bipartisan Infrastructure Law’s Wildlife Crossings Pilot Program, provided the capital necessary for the Greenland project. Furthermore, the recent passage of Colorado’s Wildlife Collision Prevention Act aims to create steady, long-term funding. Signed into law this spring, the bipartisan legislation authorizes an optional vehicle registration fee dedicated to wildlife collision prevention starting next year. These funds are vital for restoring connectivity between fragmented landscapes, allowing species to migrate safely to their seasonal ranges across the state.

Public engagement plays an equally vital role. Proactive coexistence is not merely an academic exercise; it is a collaborative effort involving the Colorado Department of Transportation, Colorado Parks and Wildlife, independent researchers, and concerned citizens. By supporting infrastructure bills and local initiatives from the Front Range to the Roaring Fork Valley, residents are taking an active part in ensuring that Colorado remains a state where wildlife and humans can share the landscape effectively.

As we move forward into the latter half of the decade, the science of safe passage will continue to evolve, integrating GPS collar data and community feedback to refine where we place our next bridges and tunnels. It is a heavy investment that requires sustained funding, precise engineering, and a deep respect for the ancient migration routes that define Colorado’s natural heritage.