Animal Influence I - Antennae The Journal of Nature in Visual Culture

Kelty McKinnon
Olin Studio’s Wild X’ing, competition finalist
ARC
In 2010, the ARC (Animal Road Crossing)
competition was initiated by Banff wildlife
ecologist Tony Clevenger, the Western
Transportation Institute, and the Woodcock
Foundation in an effort to bring innovation back
into the process of designing large infrastructure.
Interdisciplinary teams of landscape architects,
architects and engineers were challenged to
structure a better coexistence between vehicular
and animal movement networks through the
rethinking of the wildlife highway bridge. Five
teams were shortlisted from thirty-six submissions,
representing over 100 landscape architecture,
architecture, engineering, ecology, and related
firms worldwide.
The site chosen was along I-70 in West Vail
Pass, a rapidly urbanizing zone between Denver
and Aspen that passes through the White River
National Forest in Colorado. A critical habitat
linkage within the Rocky Mountains, the site is
home to a number of species including black
bear, cougar, bobcat, Canada lynx, coyote, elk,
deer, American marten, porcupine, yellow-bellied
marmot, snowshoe hare and red squirrel. I-70 is
the main transportation corridor in Colorado, and
cuts east-west, while the area’s wildlife ranges
48
typically run north-south. This portion of the pass
had multiple barriers to movement including
guardrails, median barriers and grade separation,
and species had no other choice to cross to the
other side than to cross 4 vehicular lanes. Roadkills
at the site are common, and recently included 3
Canada lynx, a federally threatened and rare
species as well as the first recorded gray wolf
since 1936 (8). For the purposes of the
competition, the site boundary was drawn 400
meters along the highway and 150 meters east
and west into the forest on both sides of the
highway. The total site area was 24 hectares.
The five competition proposals were
remarkably similar in their strategies, and the
teams were significantly complex – landscape
architects teamed with landscape ecologists,
road ecologists, structural engineers and
architects. The 5 shortlisted candidates were
predominantly led by landscape architects-
Diana Balmori Associates, Janet Rosenberg
Associates, Michael Van Valkenburgh Associates,
The OLIN Studio, and an architecture firm from the
Netherlands, Zwarts and Jansma. The winning
submission was titled Hyper Nature, by Michael
Van Valkenburgh and HNTB Engineers.
The schemes needed to be ecologically
responsive. The site is within the Subalpine Life
Zone, characterized by coniferous forest, alpine
meadows, riparian forests and shrub species. All
of the teams attempted to create a seamless
connection between the bridge and its
surrounding sub-alpine landscape by extending its
affiliated vegetation and surface qualities over the
bridge structure. OLIN’s scheme, “Wild (X)ing,”
planted six distinct habitats: spruce and fir forest;
xeric grassland; xeric shrubland; mesic grassland;
mesic shrubland; and wet meadow.
The schemes needed to be able to span
larger distances as well as be wider to
accommodate larger groups of animals - while
being cost effective and structurally and visually
light. In the not-too-distant future, an additional 2
traffic lanes are proposed for the I-70, as well as a
commuter rail line. In addition, the schemes were
required to accommodate and enhance an
existing bike trail. The scheme by Balmori
Associates proposed a wide, continuous beam
without any joints, constructed of laminated wood
from trees killed by pine beetles. These wider
schemes also necessitated a strategy for lighting
the underpass. Many of the schemes engineered
an arc that lifted the sides to allow light to the
interior. Olin’s scheme also incorporated a
perforated ceiling to maximize light underneath
the structure for drivers.
The proposals also needed to be adaptive
and flexible for wildlife mobility under dynamic