Teton Wilderness: The Last Place Every Native Animal Still Lives

Most wilderness areas in the American West are missing something. Grizzly bears or wolves or elk, or some combination of all three, eliminated by hunting or habitat loss before the land was protected. The Teton Wilderness, administered as part of the Bridger-Teton National Forest, is one of the exceptions.

Within the Teton Wilderness and the adjacent Yellowstone ecosystem, every large mammal species that was present when Lewis and Clark crossed the continent in eighteen oh four still lives. Grizzly bear. Gray wolf, reintroduced in nineteen ninety-five and now naturally reproducing. Bison. Moose. Elk, one of the largest migratory herds in North America. Mule deer, white-tailed deer, pronghorn antelope, bighorn sheep, mountain goat. Black bear. Mountain lion. All present.

Wildlife biologists call this a complete trophic system. Every level of the food web intact from grass to apex predator. In the continental United States, complete trophic systems exist in almost no other place.

The consequences are scientifically visible. When wolves were reintroduced, elk behavior changed. Elk that had previously grazed river bottoms heavily began moving more, staying less in any one place. Willow and aspen and cottonwood recovered along streams. Songbird populations increased. Beavers returned to stretches of river they had abandoned. The cascade of effects from a single reintroduction ran through the system in ways the researchers who predicted them admitted were larger than their models had anticipated.

The wilderness boundary is a line on a map. The ecological system it protects is something rarer than the map suggests.