News & Media

The Case for an I-70 Wildlife Bridge

by Harvey Locke (Vail Daily)
January 6, 2012

The Vail Symposium on Thursday evening gave this high Rocky Mountain community the chance to consider an important question: How to come to grips with Interstate 70 and all the benefits it brings without it cutting the landscape in two?

In no place is this question more important to people than in Vail. It is also critically important to the future of Colorado’s wildlife and to the safety of Colorado drivers.

I-70 cuts Colorado’s mountain habitat in two as it slices east-west across the north-south grain of the Rocky Mountain landscape.

Animals move around the mountains to meet their food needs and to find mates.

Just like the answer to the old childhood joke “Why does the chicken cross the road?”— wildlife crosses the road to get to the other side. Unfortunately, when wild animals cross big roads like I-70, they often get run over. And when these animals are big they can come through the windshield.

There is a better way. Highway crossing structures aided by fences that direct the animals to them are an elegant solution to a problem we can solve.

Highway 1 in Banff, Alberta, Canada, passes through a region that is ecologically very similar to Vail. There the busy divided highway has been fenced and a series of overpasses and underpasses built so that that big animals can cross the highway in safety and motorists can drive in safety, too.

Similar concerns have to led to building these structures on Highway 93 in the Rockies between Missoula, Mont., and Glacier National Park.

Farther south, some are being built now to aid pronghorn migration on Highway 189 near Pinedale, Wyo.

I-70, high in the mountains of Colorado, is an obvious place to build them next. Overpasses are needed here for large mammals like moose and furbearers like lynx that are making a comeback after reintroduction.

Some really good highway mitigation work has already been done for elk and deer on I-70 in the less snowy Eagle area. The work done on I-70 to protect the Colorado River through Glenwood Canyon is also first rate.

Now it is time to address the needs of the furry animals of the high country in places like Vail Pass and the sub-alpine forest east of the Eisenhower Tunnel below Loveland ski area.

The Colorado Rockies are not an island. They need to be ecologically connected to the Rocky Mountains farther north to stay healthy.

The best and most secure habitat for furry animals in Colorado is south of I-70 in the Collegiate Peaks and the San Juan Mountains.

One lynx reintroduced in the San Juans bred there for a few seasons and then traveled north as far as Banff National Park in Alberta, Canada.

Recently a wolverine from the Greater Yellowstone area has made it south of I-70 to the Collegiate Peaks.

Colorado is richer for their return. We know from experience with Highway 1 in Banff that they will use highway crossing structures if we build them.

Because of the obvious importance of I-70 to the big picture of wildlife crossings in North America, the ARC highway crossing structure design competition was set for a site on Vail Pass. Designers from across North America and Europe competed to come up with the most elegant and cost-effective design for a wildlife crossing structure over I-70.

Harvey Locke is a strategic conservation adviser to the WILD Foundation in Boulder. He lives in Banff, Alberta, Canada. For more information about the event, see or call 970-476-0954.