This story also appeared in Mountain Journal Pronghorn in the road, Lamar Valley, Yellowstone National Park. Roads present one key barrier to wildlife movement across a landscape. Trump Highway, as S. 4484 would create, would expand Highway 287 by ad ding lanes, a median, a wider shoulder and a network of on and off exit ramps. Credit: Jacob W. Frank / NPS Last month, U.S. Senator Cynthia Lummis (R-Wyoming) cosponsored a bill that could convert U.S. Highway 287 into an official federal throughway that would be known as Trump Interstate. The bill, called the “I-47 Future Interstate Act,” or S. 4484, was introduced to the U.S. Senate on May 11, and has since been referred to the Committee on Environment and Public Works. A press release from the bill’s cosponsor, U.S. Senator John Cornyn (R-Texas), said the expansion would “increase economic growth and improve safety.” Since its introduction, opponents of the bill have called it a “political statement” since it allocates no funding or mandates for the interstate’s construction.  But in a rapidly developing region like Greater Yellowstone, scientists have questions: What would a highway expansion do to the surrounding ecosystem? And what does this project look like on the ground? Highway 287, the “future” Interstate 47, stretches 1,791 miles from Choteau, Montana, to Port Arthur, Texas, and en route passes through Idaho, Wyoming, Colorado and Oklahoma. I-47 slices through the heart of Greater Yellowstone, one of the largest, nearly intact temperate-zone ecosystems on Earth. Within its bounds is a mass of biological diversity: thousands of native plants, several hundred bird species and 67 types of mammals, including the large and often charismatic ungulates and predators. This unique biodiversity relies on a healthy landscape that is balancing development with connectivity. Highway 287, which would become Trump Highway if S. 4484 passes, spans nearly 1,800 miles from Choteau, Montana, to Port Arthur, Texas. Credit: Google Andrew Jakes, a senior research scientist for the Wyoming Migration Initiative, said the highway expansion would contribute to a “death by a thousand cuts.” The impacts would be both direct and indirect, and include not only those from the expansion’s physical features — two additional lanes, a median, a wider shoulder, a network of on and off exit ramps — but also what comes with increased paved surfaces, such as ecological consequences and wildlife behavioral changes.   The top 10th percentile of roads with wildlife-vehicle collisions per mile per year, for each state in the western U.S. Credit: CLLC and WTI West-Wide Study to Identify Important Highway Locations for Wildlife Crossings, 2023. One impact could be direct mortality as a result of increased wildlife-vehicle collisions. A 2023 study conducted by the Center for Large Landscape Conservation and the Western Transportation Institute found stretches of U.S. 287 where wildlife-vehicle collisions per-year, per-mile were in the top 10th percentile across the West (sections between Lander, Wyoming and Moran, and north of both Three Forks and Helena, Montana). WVCs are expensive, too, costing Western states an estimated $1.6 billion per year, according to the same study. Beyond direct mortality, indirect impacts are oftentimes more important to consider.  Increased traffic volumes, increased speeds, increased freight and long-haul trucks. Air pollution, noise pollution, light pollution. The linear infrastructure of transportation corridors such as fences, powerlines, railroad beds, and in the West especially, natural features like streams or rivers. All of these, Jakes said, natural or anthropogenic, would change the landscape. And wildlife would have to navigate them. Roads, highways and interstates have been well documented as semi-permeable or complete barriers that significantly affect an animal’s ability to move or migrate.  Take Interstate 80, a four-lane corridor spanning southern Wyoming that provides an active means for commerce, as I-47 would aim to do. While it was completed more than 50 years ago, the consequences of I-80’s location — in the middle of established mule deer and pronghorn migration corridors — have only recently become more fully understood due to advancements in technology allowing researchers to precisely track animal movements. In a 2021 study in the Journal for Wildlife Management, researchers who used GPS-collars on seven pronghorn populations found that the ungulates were 300 times less likely to cross interstates compared to state highways. A grizzly bear sow and cub cross a road in Grand Teton National Park. Increased barriers to wildlife movement, such as new road construction and improvements, are squeezing wildlife across Greater Yellowstone and the West. Credit: C.J. Adams / NPS Liz Fairbank, a road ecologist for the Center for Large Landscape Conservation, also pointed to Montana’s Madison Valley where U.S. 287 runs through a region that already has concerns about the intersection of roadway safety and wildlife health. Among other things, the landscape surrounding the two-lane highway is an important winter range for pronghorn, she said, and they’re a sensitive species.  When a road reaches 3,500 AADT, or annual average daily traffic, it becomes a significant barrier for pronghorn, she said. “At 5,000 AADT, the road can be a complete barrier. Right now in the Madison Valley, we already have some roads over 4,000.”  In response, a broad coalition of organizations and community members called Madison Passages was formed in late 2025 to raise awareness and improve safety for people and wildlife on U.S. 287. Jakes explained there are many reasons why animals need to move easily across a landscape: to access higher quality forage, to reach historic calving or fawning grounds, and to flee unpredictable conditions such as megafires, severe drought or extreme winters — which are all becoming increasingly unpredictable in location and frequency each year as a result of a changing climate. “So you can imagine that if an even bigger roadway is put in,” he said, “it would continue to diminish ecological connectivity and make it that much more difficult and dangerous for wildlife to access these areas.”  Bighorn sheep stand on US-93 South by Sula, Montana. Credit: Kylie Paul And while different species, and even different herds, demonstrate varying movement patterns and plasticity, from daily movements within an annual range to long-distance migration between seasonal ranges, “it’s absolutely vital that we maintain the opportunity for these animals to move if we expect them to be able to survive,” Jakes said. Biologists are also studying how roads impact birds, reptiles and amphibians, showing population declines, isolation due to fragmented habitats and behavior modifications. For these wildlife health factors alone, Jakes and Fairbank say the I-47 Future Interstate Act is misguided. “With an interstate, there would be a lot more people, goods and materials traveling from point A to point B, and I get it, economically it’s beneficial,” Jakes said. “But with that enlarged footprint that includes increased traffic volumes and speeds, there are serious ecological consequences that people need to be aware of.”  Fairbank pointed to the fact that, even without an interstate project, Greater Yellowstone is already under pressure from development and increased visitation and traffic. “This would only further exacerbate all of the things that we’re already trying to catch up on and mitigate here,” she said. The post Questions of connection: What would a Trump Interstate mean? appeared first on Montana Free Press. ...read more read less