In the Cascade Range, the question isn’t why animals cross the road, but how they can do so without becoming salamander road-cakes or elk a la SUV.
The answer, say
Washington state transportation officials and biologists, lies
under and over a humming mountain highway.
In June, the
state’s Department of Transportation released plans for
widening a 15-mile section of I-90 east of Seattle, smack in the
middle of a major wildlife thoroughfare. To reduce auto-animal
collisions, the plans include several types of wildlife passages
modeled after successful critter crossings in Arizona and Florida
and on Banff’s Trans-Canada Highway (HCN, 2/7/05: Caught in
The road improvement project, slated to
begin in 2011, will be a "showpiece" of ecological highway
building, says Kim Vaughn, a transportation department design
supervisor. Work could include improving culverts to aid smaller
mammals and reptiles, creating hydrologic connections for fish and
amphibians, and building the country’s first wildlife
over-crossing, a wide bridge carpeted with native soil and plants.
"We’re targeting a wide range of species, from low-mobility
salamanders to large carnivores," Vaughn says.
Clevenger, a Montana State biologist, says getting animals across
safely is just the beginning: "Habitat is getting chopped up and
biodiversity is getting scarcer." The real boon of the project, he
says, will be reconnecting the wildlife living on both sides of
I-90 in the Wenatchee National Forest.
So far, the state
has committed $388 million to the highway improvements, most of
which will go to road widening and avalanche-safe tunnels. That
wildlife welfare is also addressed thrills Jen Watkins, a
spokesperson for the I-90 Wildlife Bridges Coalition, which pushed
for including animal crossings in the project: "It’s critical
for us to attack the last barrier for wildlife." The public can
comment on the project through Aug. 5.