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Colorado has a mule deer problem. The iconic ungulates, named for their long, floppy ears, have experienced a recent, dramatic decline in this state. No one knows why this is, but one thing’s for sure: Our region’s busiest, best-known highway probably isn’t making it any easier for them. I found this out myself the hard way (the doe my car collided with took it even harder) several weeks ago on the road from Montrose to Ridgway.

I’d been traveling at dusk along U.S. 550, a narrow, two-lane road that is the main artery from Montrose to points south: Ridgway, Ouray and Durango via Red Mountain Pass. The Montrose-to-Ridgway section is one of the 10 most hazardous roads in the state for drivers and wildlife, according to a 2006 report produced by the Southern Rockies Ecosystem Project for the Colorado Department of Transportation. Since the report, CDOT has made a number of improvements to the road to help drivers — its first priority –– and wildlife from coming into contact with each other by lowering speed limits from 60 mph to 55 mph in migration season;  erecting eight-foot-tall wildlife fencing; building “escape ramps,” grassy berms that allow animals trapped on the street side of the fence passage to the safe side, and constructing an underpass for large wildlife outside of Colona.

Protecting people and wildlife from each other is crucial this time of year because herds have begun migrating. As snow increasingly covers the terrain, animals –– chiefly mule deer, which are not adapted to winter at higher elevations –– descend from their summer ranges in the San Juans and the Cimmarons to lower elevations at the bottom of the Uncompahgre Valley, where temperatures are warmer and there is plenty to eat and drink.

And that’s the problem. As animals move down from the high country, their contact with cars increases: CDOT says accidents are up 15 percent in 2015, and a total of 3,960 wildlife-vehicle collisions have been reported in the state over the past year. What’s more, as reported in part 1 of this story (find it at tinyurl.com/psd83db), wildlife fencing, the very thing designed to keep these animals safe, could actually be killing them.

It’s not that the fences themselves are bad, but wildlife fencing only really works if it also offers animals a way to cross the road. Crossing spots are crucial to maintaining “linkages,” natural highways necessary for migration. And a report published by CDOT in May found that, although the number of collisions on 550 is down and money has been saved as a result of the fencing and escape berms, there are too few places for ungulates to cross. For example, the report’s authors noted that in Arizona, the standard number of “jump-outs” per mile is two, and in Utah it is four; yet there is a two-mile stretch along 550 (in one of the worst stretches for accidents) without even one escape ramp. What’s more, the fencing hasn’t been maintained. Researchers with Colorado State University and the Nature Conservancy in Fort Collins counted 34 openings on an eight-mile stretch of road that might allow ungulates or other wildlife access to the right of way, and 20 of the openings were “easily passable” by deer. As for the underpass CDOT constructed, “Deer kind of have to drop down from the highway to use it, and a deer doesn’t want to do that,” said Colorado Parks & Wildlife Biologist Brad Banulis. “I could see mountain lions and bears not hesitating.”

Add it all up — too few escape berms, poorly maintained wildlife fencing and a single underpass that deer are reluctant to use –– and the results can be disastrous for the long-term health of a herd. Monique DiGiorgio, who supervised the Southern Rockies Ecosystem Project report, has called this lack of access to the other side of the roadway “tragic and shameful. An escape berm is a Band-Aid,” she added. “It is not a solution.”

Mule deer need to be able to reach their winter migration grounds, a huge patch of real estate bisected by Highway 550. Last week, I observed a buck standing alone along the dry edge of Ridgway Reservoir, gazing across the fencing at the other side of the road. If the fence hadn’t been holding him back, he would have crossed and been long gone; this time of year, migrating deer should be hoofing it down valley to a lower elevation. I’ll never know if this one made it there.

“Fences can be very effective if they’re functional and don’t allow crossing,” said USDA Wildlife Biologist Sandra Jacobson. “The whole principle is, you want to a) keep animals off the highway, and b) direct them to where to cross. Some can work around fencing and still survive, but for others, crossing is a matter of life or death. In the intermountain west, the poster children for these are the migratory mule deer and pronghorn. They’re highly motivated to move. They summer in the higher elevations, and if they can’t back down to their winter ranges, they will die.”

It’s not just worrisome that a single group of animals may die over one winter because they can’t cross the road. The more serious risk is that two sets of animals, or over time, many more, can become trapped on either side of a fence for years and never interbreed. According to the SREP report, some biologists believe this has already happened, and that the southern part of 550, closer to Ridgway, has become a “choke point” blocking the passage of elk from east to west as a result of the wildlife fences.

Montana State University wildlife research ecologist Anthony Clevenger specializes in wildlife crossings and has published papers on everything from bears to wolverines, puma to pine martens. “Mule deer play a part in the greater ecosystem,” he said. “There are thousands of them, and there are also a lot of carnivores and predators out there that rely on this species, as well.”

He added, “If a herd becomes separated [due to wildlife fencing], you’ve effectively split it in two. The population is halved. If they’ve been migrating to a certain region for thousands of years, feeding, reproducing and calving — and now they can’t return to the same place –– the risks can be huge.”

Photo credit: ARC Solutions. Concept design for the winning entry in the 2010 ARC International Wildlife Crossing Infrastructure Design Competition by HNTB with Michael Van Walkenburgh and Associates.

Wildlife crossings: Toward the future

A few spots in the world are esteemed for wildlife crossings. The Trans-Canada Highway in Banff National Park, Alberta, which Anthony Clevenger has studied extensively, is perhaps the best known. It includes 50 miles of highway fencing, 38 underpasses and six overpasses to help grizzlies, deer, elk, black and grizzly bears, wolves, cougars, coyotes and moose cross the road safely. Canada’s may be the most famous, but wildlife traverses exist all over the world. Six hundred crossings in the Netherlands protect the European badger, as well as wild boar, red deer and roe deer; koalas, wombats and kangaroos use an underpass in Victoria, Australia. Closer to home, wildlife crossings can be found coast to coast, helping to safeguard everything from the endangered desert tortoise in San Bernardino County, California, to Florida, where 24 bridges and 12 underpasses in Collier and Lee counties protect the Florida puma.

Wildlife crossings are more sophisticated today than in the past, and as the field of transportation ecology continues to grow, less expensive, even transportable methods of construction and set-up (as opposed to traditional underground tunnels, or overpasses made of static concrete) are being added to the options of what’s available. The costs in traffic accidents averted and wildlife saved “are a win-win for everyone,” said Renee Callahan, partnership coordinator for ARC (Animal Road Crossing) Solutions, a nonprofit group dedicated to improving human safety, wildlife mobility and landscape connectivity. As global warming continues, migration patterns will change, she adds, and so too will places where animals traverse the highway. Thus, it is in everyone’s interest to remain proactive about crossings in order to keep all of us safe.

A promising project: Highway 9

Photo credit: Colorado DOT. One of the five new underpasses to be built on Highway 9.

Earlier this fall, the initial part of an ambitious road-and-wildlife-crossing safety project was completed in northern Colorado, the first of its kind in the state. Five underpasses and two overpasses (considered the gold standard among traverses because large animals more readily use them) are being constructed on an 11-mile stretch of road in Grand County along State Highway 9, between Kremmling and Green County Reservoir. Highway 9 is one of the most notorious passages in the state for wildlife deaths and, just like U.S. 550, bisects a major winter migration corridor. The project was fast-tracked by CDOT under its Responsible Acceleration of Maintenance and Partnerships (RAMP) program, in which local governments kick in 20 percent of a project’s total cost. (Hedge fund billionaire Paul Tudor Jones’s Blue Valley Ranch donated nearly $5 million to the $46 million project, and local residents came up with the rest.)

“A lot of states are tightening their budgets for transportation projects,” said Renee Callahan of ARC. “To me, the beauty of a public/private partnership is that everyone can get involved, and it allows a state DOT to get these projects on a shortlist.”

Colorado State Biologist Michelle Cowardin, who has worked closely on wildlife mitigation efforts on Highway 9, is especially pleased about the new overpasses.

Photo credit: Colorado DOT. The first wildlife overpass in Colorado, on Highway 9.

“We’ve found that some animals [such as deer and elk] hesitate to use underpasses, because they can’t see all the way through to the other side and think something might be hiding in there. They feel like they’re prey,” she said. “Overpasses are more open and are not as threatening.”

Meanwhile, the same animals that readily use underpasses happily take to overpasses.

“Studies say that every consecutive year, more and more animals approach a new crossing structure,” she said. “With overpasses, they do it sooner.”

Back in Montrose and Ouray counties, it’s not certain when, or even if, any further improvements are planned for wildlife crossings on Highway 550. Said Nancy Shanks, Region 5 Communications Manager at CDOT, “We have competing needs — wildlife safety and driver safety –– and fencing is absolutely the most cost-effective mitigation we can do.” She adds, “We take wildlife hotspots into consideration in our planning, and where we constructed the Colona underpass was one of the worst” (wildlife-vehicle collisions around the hotspot are down considerably since completion of the underpass). CDOT can only undertake wildlife-mitigation projects in connection with a highway construction project and must deploy its “limited amount of funds” across several regions, Shanks said. The next project in our region, which may include wildlife mitigation, targets a section of U.S. 550 around the Billy Creek Wildlife Area. Pending funding, Shanks said, it could begin as soon as 2018.

Not all of Highway 550 has wildlife fencing along it. It isn’t known what effect the resultant  patchwork has had on the ungulates. What percentage of migrating mule deer might be expected to use the Colona underpass, or continue down valley along the fence-line and duck out at just the right time in one of the open areas to make it across the river without being hit, for example? “To find out, you’d have to do a big study on whether there has been a net decline in deer populations along 550,” said Montrose Department of Wildlife Manager Renzo DelPiccolo. “And as far as I know, this hasn’t been done yet.”

Perhaps it will. As DelPiccolo says, the fencing on Highway 550 “Has not been without consequences” for deer and elk. “I think that will change,” he said. “The more that we’ve gone to the eight-foot fences, the more we’ve seen an impact on wildlife. I believe CDOT is paying attention.” He points to a CDOT project on U.S. 160 outside of Durango, another hotspot for wildlife. “It’s not that they’re doing anything wrong here,” he said, “but they’re doing more there. They are trying to design things differently, with wildlife in mind, rather than simply protecting motorists.”

That should be the way of the future. As Karsten Heuer, president of the Yellowstone to Yukon Conservation Initiative, points out in a documentary on Canadian road crossings and habitat connectivity entitled “Highway Wilding,” “We’re not in an age of restoration. We’re in an age of keeping what we already have. Of conserving the connectivity that all the science is showing us is so crucial. And we have the know-how…we’ve proven that these [things] can be done, and be successful, and can meet the needs of the animals. And if we don’t do it, then that really is a conscious decision on our part. We have no excuse for not doing it and then down the road saying, ‘what happened to the wildlife?’”