Colorado will soon make history with a long-awaited wildlife crossing project on Interstate 25, but the state faces fiscal headwinds in continuing its plan to build other facilities to help animals avoid highways. No federal grant money was awarded to the Centennial State for the current fiscal year and the Trump administration has frozen some previously awarded funds.

And money allocated for overpasses and underpasses by a recent state law has dried up as budget challenges have discouraged the state Legislature from continuing to appropriate funds first authorized in 2022.

Nevertheless, four significant infrastructure developments to benefit wildlife are completed, underway or planned in the state. In addition to the Greenland Wildlife Overpass Project in southern Douglas County, the state Department of Transportation has finished a crossing on Colo. 9north of Kremmling and another on U.S. 160 west of Pagosa Springs. The fourth, which is not complete, is on Interstate 70 near Vail Pass. Colorado and New Mexico have also been working on a wildlife crossing at Raton Pass, on I-25 at the states’ joint border.

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Renee Callahan, the executive director of ARC Solutions, a nonprofit organization that guides states and other interested governments in building wildlife crossings, is especially enthusiastic about the latter project.

“Pretty much every species that you can think of that is in Colorado, is in this area,” she said, pointing to the nearby Fishers Peak State Park that is home to bears, cougars, deer and elk. “And I think the other thing that makes that one really important is (that) wildlife don’t pay attention to state lines.”

“Colorado is obviously one of the leaders in addressing the problem of roadkill and wildlife collisions,” Ben Goldfarb, a journalist and the author of the recent book “Crossings: How Road Ecology is Shaping the Future of Our Planet,” said. “Colorado has built more wildlife crossings than the vast majority of states and it’s in the process of building more. We see fantastic projects all over the state.”

The state is not alone in the effort to confront the problem of wildlife mortality and human suffering when animals and motor vehicles collide.

“Wyoming has also been working on this issue for, easily, as long as Colorado, if not possibly longer,” Callahan said. “Wyoming has put together, you know, a priority list of their crossings, and they’re really kind of setting them up and knocking them down. California has been a leader in this. They are building the Wallace Annenberg wildlife crossing over the 101, which is essentially 10 lanes of traffic that is essentially impermeable to wildlife.”

In addition to Colorado, Alaska, Arizona, California, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington and Wyoming have received money from the federal government to build wildlife crossings.

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Colorado has built more wildlife crossings than the vast majority of states and it’s in the process of building more. We see fantastic projects all over the state.

But, unlike most or even all of those states, Colorado has no dedicated state funding for wildlife crossing projects. That leaves the state even more susceptible to political winds blowing out of the nation’s capital than are caused by ups-and-downs in federal financial appropriations. The U.S. government’s source of dollars, the Federal Highway Administration’s Wildlife Crossings Pilot Program, is part of a legal battle that erupted earlier this year when the Trump administration froze grants to states from agencies across the federal government.

WCPP is available to support projects that states, Native American tribes, and local governments undertake. Authorized by the Infrastructure Investment and Jobs Act of 2021, Congress approved $350 million for spending on WCPP each year. Grants were awarded for fiscal years 2023, 2024 and 2025. Among the projects that received a grant is the Greenland Wildlife Overpass, which is under construction and expected to be completed in December.

The Greenland Wildlife Overpass is extensive and is expected to benefit large numbers of animals. Chuck Attardo, the Colorado Department of Transportation’s I-25 south corridor environmental project manager, explained that the Greenland Wildlife Overpass is a system that includes not only a 40,000-square-foot overpass, but a series of underpasses and wildlife fencing along the highway and on the overpass, too.

“There’s actually two types of fences on the overpass,” he said. “There’s the 8-foot wildlife exclusion fence. And we need to create a funnel on either end of the overpass that gets elk and pronghorn to use this.”

Among the largest crossings on the planet

Investment of public resources in wildlife movement infrastructure on roads and highways has been shown to produce a positive economic return. This occurs because the overpasses and underpasses result in a sharp downturn in motor vehicle-animal collisions. According to a 2021 report from The Center for Large Landscape Conservation, those accidents kill more than 200 people, and injure more than 26,000 more, every year in the United States. Avoiding them, the Federal Highway Administration said in 2008, saves more than $8 billion each year. In Colorado the annual cost of wildlife-motor vehicle accidents is about $313 million.

The most expensive crashes involve large ungulates. On average, the economic cost of hitting a deer is about $19,000, while smashing into an elk causes expenses of about $73,000. And if a motorist is unfortunate enough to make contact with a moose on a highway, the bill is likely to be about $110,000. If a motorist and an antelope, bear, bighorn sheep, or cougar collide on the highway, the costs would be proportional to the animal’s size. The expenses include vehicle repairs, health care to recover from an injury, outlays associated with any human deaths in the wreck, and a “passive use value” — or the inherent value of an animal species’ presence — according to the center.

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Wildlife benefit very substantially from overpasses and underpasses.

“Wildlife crossing structures in the form of overpasses and underpasses in combination with wildlife fencing are proven to reduce wildlife-vehicle collisions by an average of 87 percent for animals deer-sized or larger, while allowing for their safe movement across roads,” concluded an April 2015 article published by ARCeport. One 2001 study found that a wildlife crossing reduced highway hits of deer and elk by 96 percent after installation of a Canadian overpass.

Colorado’s Greenland endeavor is likely to save even more wild lives. CDOT has suggested that 90 percent of wildlife-human motor vehicle accidents will be avoided. And the overpasses have been shown to be effective in allowing large mammals to move along migration corridors. A paper by scientists from British Columbia that examined wildlife crossing structures in western North America concluded that well-designed overpasses doubled the likelihood of successful large ungulate and large predator migration relative to poorly-built bridges.

The Greenland Wildlife Overpass will feature a bridge more than 200 feet long and about 200 feet wide that will soar across six lanes of freeway traffic. The overpass will be among the largest roadway wildlife crossings on the planet. Intended to tie together two wildlife corridors, it will allow large herbivores, like elk, mule deer, and pronghorn, to move between them. Predators, too, will benefit from the structure and its associated wildlife fencing and underpasses.

Legal challenges to funding freeze

The expected benefits Colorado’s new overpass did not stop the Trump administration from freezing WPCC grants earlier this year. On Jan. 20, on the first day of his second term, President Donald Trump issued two executive orders that mandated federal agencies, including the U.S. Department of Transportation, “​​immediately pause the disbursement of funds appropriated through” two significant laws enacted during the Biden administration: the Inflation Reduction Act and the IIJA. Others froze funding under separate federal grant programs. The White House explained that the executive orders applied to “all activities related to obligation or disbursement of all Federal financial assistance,” including for wildlife crossings.

A coalition of states, including Colorado, sued to force the federal executive branch to release those funds. On March 6, U.S. District Judge John J. McConnell issued an injunction that blocked the White House effort to prevent outflow of grants to states. The judge, appointed by President Barack Obama in 2011, sharply criticized the grant freeze.

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“​​It is difficult to perceive any rationality in this decision — let alone thoughtful consideration of practical consequences — when these funding pauses endanger the States’ ability to provide vital services, including but not limited to public safety, health care, education, childcare, and transportation infrastructure,” he wrote.

The administration asked the U.S. Court of Appeals for the First Circuit to put a hold on the preliminary injunction that McConnell imposed, but that request was turned aside March 27.

Department of Justice lawyers told McConnell during proceedings in his court “that there is no date written into the EOs or the OMB Directive or instructions when the freeze will end but argued that the funding recipients can be assured that it will end eventually,” according to McConnell’s order. But there is not yet any indication of when Colorado’s additional expected WCPP funds will arrive.

“Though that money was supposed to be released more than six months ago, it is still being held up,” Attardo said.

The continued blockade is at odds with what appeared to be a bipartisan commitment to federal funding of wildlife crossings, Goldfarb added. He said some projects outside of Colorado appear to be receiving WCPP money, but he cannot see any logical explanation for the disparity.

“I think we’re seeing this weird contradictory signal where some projects are getting the funding they’re owed and some are not,” Goldfarb said. “I’m not sure what determines which succeed and which are illegally, in my view, having funding withheld from them.”

“It is theoretically a nonpartisan issue,” he added. “But at the same time spending any money is kind of partisan in Washington right now.”

One concern is that, even if the grant money is released, the state may not have the time to fulfill a grant agreement with the Federal Highway Administration, which generally specifies a deadline for the funds to be committed to a project.

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“They usually have an amount of time that they are in effect for,” Callhan said. “Let’s say it’s around three to five years, typically. But if you don’t obligate, which in Federal Highway (Administration) language means, ‘sign a contract for that grant before those dollars expire,’ they will go away, effectively, within that time frame.”

She said that, were that to occur, states would have to convince federal legislators to renew the funding. “So I don’t see this grant coming back under this Congress and maybe the next Congress,” she said. And, “even then, you know, not under the executive branch.”

Another problem that plagues state, local and Native American tribal wildlife crossing project managers is the possibility that the federal grants could be pulled back by the highway administration, especially given a Trump administration effort to effectively re-write existing grant agreements.

“The concern that I’ve heard from some states is that they sign a contract now underneath the (injunction issued by McConnell), which basically says ‘these terms don’t apply for now,’ but x years down the line, when (the states’ current) lawsuit is finally decided (and) if the Supreme Court (says), ‘yes, you can put whatever conditions you want in,’ then those states are potentially going to be in a position of having to disgorge those federal dollars,” Callahan pointed out.

Colorado’s coffers are unlikely to be of much help in resolving the financial uncertainty. Although the state General Assembly enacted a law in 2022 that provided some funding for wildlife crossing projects, the money it made available is no more. Senate Bill 22-151 established a “wildlife safe passages fund,” with $5 million from the state’s general fund, and the Legislature added another $500,000 to it in 2023, but that resource is tapped out.

“Since then, we haven’t gotten any more money out of that,” Attardo explained.

The state’s recent budget crisis, which pushed Governor Jared Polis to convene an August legislative special session, has not yet resulted in any further damage to the state’s commitment to fund wildlife infrastructure on its highways. But the Legislature rejected a bill during this year’s regular session that would have imposed a fee on insurance policies to pay for crossings. House Bill 25-1303 did not make it out of the Senate Finance Committee.

Goldfarb views an enduring and fixed source of state funding as essential to continued progress to address the need for wildlife overpasses and underpasses.

“We see lots of states earmarking funding for this issue,” he said. “New Mexico has done it. Utah has done it. California has done it. Oregon has done it. Having that secure, deviated, auto funding is really important to be able to fill the matching requirement.” Goldfarb referred to FHWA guidelines that require states to put up a portion of the total cost of a project to receive WCPP funding.

10s of millions of bees a day

In general, roads are extremely dangerous to wildlife. As many as 10 million amphibians, birds, mammals, and reptiles are killed on them every day. Hundreds of millions of vertebrates, including at least 340 million birds, die on U.S. roads every year.

Some of the animals that suffer the most from meetings with largely hairless primates piloting large machines on concrete or asphalt surfaces are endangered or threatened. And the causes of their deaths may be dominated by those encounters. For example, the red wolf — a canid formally known as Canis rufus that is native to North Carolina — loses a significant fraction of its population to motor vehicle collisions each year.

The critically endangered ocelot, a felid known to live in Texas, is also known to be especially vulnerable to population loss resulting from encounters with human motorized behemoths.

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The Federal Highway Administration told Congress in 2008 that “road mortality is believed to have affected the population survival probability for multiple species” known in the U.S., including the moor frog, leopard frog, spotted salamander, timber rattlesnake, pond turtles, hedgehog, badger otter, Florida panther, Iberian lynx, and Florida key deer, as well as the ocelot. Among mammals, the most commonly killed are white-tailed deer, raccoons, and opossums, according to a paper published earlier this year.

Some animals that commonly draw awe from Coloradans are among those particularly susceptible to vehicle collisions. Mountain lions, for example, die when hit by motor vehicles at a rate of one to two per week in California. More than 600 were killed in accidents in the Golden State between 2016 and 2023. Deer, too, suffer in great numbers. Nearly 50,000 lost their lives on California highways in 2023, according to the Road Ecology Center at the University of California at Davis.

Even more crushed by the onslaught of vehicles are invertebrates. The toll among insects in America is difficult to fathom. Billions, according to a recent Atlantic Monthly report, are likely killed on roads every year. They include 10s of millions of bees every day, just in the Western states.

“Roadkill is not only eliminating animals, it’s in many cases eliminating those healthy animals that populations need to remain strong,” Goldfarb told NPR in Sept. 2023.

And the problem is getting more severe as animals seek to move in a quest to cope with climate change. Goldfarb explained, in the same NPR interview, that warming temperatures “make it even more important that we give them opportunities to cross highways.” “They’re trying to find new habitats and roads are preventing them from doing that,” he added.

In Colorado, CDOT and the Colorado Parks and Wildlife have worked to mitigate some of the toll inflicted on the tiniest denizens of our world. The state has a rare invertebrate crossing in place. “You do see some instances of mitigation for small critters,” Goldfarb said. “A lot of the small I-25 underpasses will have sticks and brush in them so that rodents can follow them.”

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“We build more crossings for ungulates because there’s a human safety connection for them,” he continued. “We need to be thinking about the smaller, rarer species as well.”

The agencies have been working to evaluate the feasibility of tarantula passages. The large theraphosids move in huge numbers in parts of Colorado every autumn as they seek mates.

“If we produce a lot of culverts or underpasses, things like tarantulas, box turtles, other reptiles and amphibians can use those culverts as well as other insects and not get squished,” Richard Reading, the vice president of science and conservation at Butterfly Pavilion and an ecologist, told CBS News in 2022.

The state has plans for additional wildlife crossing infrastructure on the Eastern Plains. Those projects, though, along with — possibly — the Vail Pass crossing, may not survive the fiscal gauntlet that has fallen over the federal Wildlife Crossings Pilot Program this year. Attardo said the need for those additional projects is extensive, estimating that “hundreds” are necessary.

“Estimates are probably in the billions of dollars statewide,” he said, referring to the financial investment. “But there really is nothing in the queue to go next.”

Colorado will prioritize three projects once the federal grant freeze is resolved: the Raton Pass crossing, a project on U.S. 40 near Empire, and a structure on U.S. 160 west of Durango.

“Those three projects are going to apply for the wildlife crossing pilot program funding,” Attardo said. “This round, we expect to get money again.”

Some wildlife advocacy organizations hope to convince Congress to increase the annual federal WCPP allotment of $350 million to $500 million in this year’s federal transportation bill. In one example, Madeleine West, the public lands director at the Theodore Roosevelt Conservation Partnership, told a Senate committee in Nov. 2023 that funding of wildlife corridor projects “Is the top conservation issue for hunting and fishing organizations.”

However the fiscal details are worked out, Goldfarb emphasized the urgency of continuing work on wildlife crossings.

“On the one hand Colorado is doing a lot,” he said. “On the other hand it’s not nearly enough to address the massive scope of the problem.”