By Joel Warner
By Michael Roberts
By Alan Prendergast
By Michael Roberts
By Michael Roberts
By Amber Taufen
By Patricia Calhoun
By William Breathes
"We call it the Berlin Wall of wildlife," says Sloan Shoemaker, executive director of the Wilderness Workshop, a conservation watchdog group based in Carbondale. "It poses a number of problems for keeping healthy ecosystems from unraveling."
Elk aren't the only megafauna that find the highway deadly. Deer account for five times as many animal-vehicle collisions in the state as elk do, including numerous I-70 crashes. In the past ten years, the Colorado Division of Wildlife has spent millions to re-establish the lynx in Colorado forests, only to see several of their cats end up as roadkill. Four have died on I-70, including a pregnant female. Five years ago, a wolf from Yellowstone National Park, the first to arrive in Colorado in decades, made it as far as Georgetown before being struck and killed while crossing the highway.
DiGiorgio, Shoemaker and other activists want to see an overpass built for wildlife on the west side of Vail Pass, a key connection point between national forest lands on either side — and the same area where two of the dead lynx were found. The need for a large crossing structure in the area was first identified by CDOT several years ago. The bridge would be covered with vegetation, including trees, and would be the first structure of its kind in the United States. It would serve a wide range of species, including elk and deer, bighorn sheep, moose, black bear, coyote, lynx and the lynx's favorite meal, the snowshoe hare. It would also cost an estimated $12 million.
At a time of budget shortfalls and crumbling infrastructure, the idea of investing a few million in a "green bridge" over I-70 exclusively for animal use strikes some critics as daffy. Fiscally minded conservatives have mocked the proposal; former congressman Tom Tancredo suggested hiring Dr. Dolittle "to translate directions into bear and deer language."
"It's a tough sell, frankly," acknowledges Shoemaker. "When bridges are collapsing, it's hard to argue that money should be diverted from that to this. But this bridge is a priority for a number of economic as well as ecological reasons."
A few years ago, crossing advocates successfully lobbied for a congressional earmark to study the proposal. CDOT has since spent most of the $420,000 grant on research and preliminary design work. Finding the money to build the bridge remains a challenge, but a modest portion of federal stimulus dollars is already being directed toward two wildlife crossing projects elsewhere in the state — underpasses along U.S. 285 and escape ramps on U.S. 550 between Durango and Ridgway.
Establishing safe passages for wildlife is a long-term investment in the state's future, insists Julia Kintsch, an ecologist who operates her own consulting company, ECO-resolutions, and has worked on the Vail Pass bridge project for years. "There's this hangup that it's for wildlife, not for people," she says. "We need to recognize that wildlife are an important part of the world we live in, too. It doesn't always have a monetary value attached to it, but it has value to our economy. It's a large part of why people come here to recreate and to live."
Although they are rarely noticed by passing motorists, wildlife-crossing structures are hardly a new idea in this state. Researchers studying migration routes in southwest Colorado a few years ago were surprised to discover an arch culvert under U.S. 160 west of Durango, near Mancos, that dates back to the early 1970s and was designed to work with fencing in the area. The passage showed traces of recent use by elk, deer and coyote as they journeyed from one side of the highway to the other.
"Colorado was really ahead of its time," says DiGiorgio. "To think that we knew about these kind of mitigation measures and had the political will to build them way back then."
Even before the Eisenhower Tunnel was completed, leading to a staggering expansion of the ski industry, a few pioneering biologists and wildlife advocates were already studying the state's rising rate of animal-vehicle collisions and pushing for better barriers and crossing designs. Yet over the past fifteen years or so, the greatest strides in the field have been made outside Colorado.
Banff National Park in Canada has reduced collisions drastically by building a series of 22 wildlife underpasses and two overpasses, combined with gates and escape ramps, along the Trans-Canada Highway; since 1996, the system has logged 186,000 crossings by eleven different species of large mammals. Arizona has invested in elaborate fencing systems to help guide wildlife across its major interstates. New Mexico has used electrified fences and underpasses to steer deer across I-40 east of Albuquerque.
Colorado's most recent contribution to the emerging technology can be found on U.S. 160 east of Durango, in a one-mile stretch that has historically had one of the highest animal-vehicle collision rates in the state. CDOT has buried cables along the road shoulder that sense changes in the electromagnetic frequency on the surface. Such cables have been used to detect intruders in high-security facilities, but never before for wildlife. When a large animal walks by, the sensors trigger flashing warning signs, alerting motorists that wildlife are attempting to cross. The $1.2 million project has only been in operation a few months, but officials hope the system will offer a cheaper, viable alternative in areas that don't readily accommodate an underpass.