Big Pivots: Dismantling the Walls to Wildlife in Colorado

A wildlife crossing over Colorado Highway 9 between Kremmling and Silverthorne helps reduce animal-vehicle collisions in the region.
Hugh Carey / Summit Daily

Although never a big game hunter, I have killed three deer in Colorado and probably given a bull a huge headache each. That’s not to mention my carnage among rabbits and other smaller animals.
Cars were my weapon, not guns.

Driving at dusk or in the dark of night will inevitably produce close brushes with wildlife, large and small, on many roads and highways. Even daylight has its dangers.

Colorado now defines that risky, rugged edge between wildlife habitat and the high-speed travel we take for granted. State lawmakers delivered a message last year when they appropriated $5 million for wildlife connectivity involving highways in high-priority areas.



At the end of December, state agencies identified seven locations where that money will be spent. They range from Interstate 25 south of Colorado Springs to Highway 13 north of Craig near where it enters Wyoming. New fencing and radar technology is installed. Highway 550 north of Ridgway will get an underpass.

The pot was not deep enough to produce overpasses such as two crossing Highway 9 between Silverthorne and Kremmling or one between Pagosa Springs and Durango. But $750,000 if allocated to design work for intersections of I-25 at Raton Pass with an equal amount for design of an I-70 intersection at Vail Pass.



In these and other ways, Colorado can better compete for a piece of the $350 million allocated by Congress in the 2021 Infrastructure Investment and Jobs Act for improved wildlife connectivity.

This is on top of the transition of I-25 planned for the segment between Castle Rock and Monument to supplement the four underpasses installed in the widening project of the last few years.

We are turning in how we consider roads and habitat for wildlife. We have long been driven to protect human lives and our property by reducing collisions. Our perspectives have broadened. Human safety still matters, but so do the lives of animals.

When we built our interstate highway system between 1956 and, with the completion of I-70 through Glenwood Canyon, 1992, we paid little attention to wildlife. There were exceptions, such as the narrow underpass for deer in West Vail installed in 1969.

Biologists in the 1990s began to emphasize highways as home wreckers. Expanding road networks, they said, was creating islands of wildlife habitat. Fragmented habitat leads to reduced gene pools and, at the extreme, the threat of extinction of species in some areas, called extinction.

I-70 became the marquee for this. Wildlife biologists began to call it the “Berlin Wall for Wildlife”. The appropriateness of that phrase was vividly illustrated in 1999 when a transplanted lynx released just months earlier attempted to cross I-70 at Vail Pass. It tasted dead.

With that graphic image in mind, wildlife biologists held an international competition with I-70 in 2011. The goal, at least partially realized, was to discover less expensive materials and designs.
Colorado’s pace has quickened since a 2014 study documenting the decline of Western Slope mule deer populations. In 2019, an incoming Gov. Polis issued an executive order directing state agencies to work together to solve road-related problems.

Two wildlife crossings along with underpasses and enclosures north of Silverthorne completed in 2017 have been valuable examples. Studies showed a 90% reduction in collisions.

“An 80 to 90% reduction right off the bat is pretty typical for these structures,” says Tony Cady, a planning and environmental manager for the Colorado Department of Transportation.
State agencies, working with nonprofit groups and others, have crunched the data to describe the state’s 5% of highest priority road segments. This data could give Colorado a leg up on accessing federal funds.

The two studies found 48 high-priority segments on the western slope and 90 east of the Continental Divide, including the Great Plains, reports Michelle Cowardin, a wildlife biologist for Colorado Parks and Wildlife. The Craig and Meeker areas have many high priority roads, and much of I-76 between Fort Morgan to Julesburg has many high priority segments.

Some jurisdictions delve deeper. Eagle County has completed a study of wildlife connectivity, and in the Aspen area, a non-profit called Safe Passages has secured funding to begin identifying the highest priority locations in the Roaring Fork and Crystal River valleys.

These new studies testify to a shift in public attitudes. Rob Ament of Montana State University’s Western Transportation Institute says wildlife connectivity is institutionalized in how we think about transportation corridors. Rather than an exception, he says, intersections become a cost of doing business.

This also happens internationally. “My world just exploded,” he said while reciting crosses for elephants in Bangladesh, tigers in Thailand and work for other species in Argentina, Nepal and Mongolia.

In some ways a long time coming, we are redefining the relationship between highways and wildlife.

Allen Best
Courtesy photo

Allen Best publishes Big Pivots, which focuses on climate change and the energy and water transitions in Colorado. Look up more BigPivots.com.

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