Bearing down on grizzlies.

A burly grizzly bear strode across a meadow in Yellowstone National Park last spring, barely noticed by grazing herds of elk and bison. The bear, weak from hibernation, was focused on procuring an easier meal, such as scavenged bison carcasses and the tiny white blossoms that speck the forest edges.

A keystone species in several ecosystems, the grizzly (Ursus arctos horribilis) was listed in 1975 as threatened in the lower 48 states. Over 120 years, the bear's range in the continental United States was reduced to a half-dozen disconnected populations. Fewer than 1,100 grizzlies survive where there were once 50,000. Its slow reproductive rate is part of its plight, but habitat infringement is what really threatens to bring this mega-mammal down.

"No other terrestrial mammal in North America has more demanding habitat requirements than the grizzly," says Chuck Schwartz, leader of the federal Interagency Grizzly Bear Study Team. Despite the continuing threats to its survival, the bear is being considered for delisting because of increased development pressure in Wyoming, Montana and Idaho. Add in the Bush administration's recent rollback of the Clinton-era roadless rule for federal land and it's a potent one-two punch. "The grizzly remains the most sensitive to roads of any species studied in the Northern Rockies," says Margot Higgins of the Sierra Club. Grizzly bears are five times more likely to die in an area with roads or trails, according to a 1991 study by the interagency team.

The oil industry (after losing its case for drilling in Alaska's Arctic National Wildlife Refuge), has set its sights on exploring and building roads in such areas as the Rocky Mountain Front in Montana's Lewis and Clark National Forest and the Powder River Basin in Shoshone National Forest in Wyoming and Montana, which have varying levels of protection.

While it may seem anathema for corporations to turn a profit on public lands, the West has a long history of just such commercial development. In the face of the multifarious land uses that have shaped the region, remaining grizzly territory stands as a western Eden. The reintroduction of wolves in 1995 has helped restore a natural balance visible to even inexperienced observers.

The delisting of grizzlies could occur anytime between now and 2005. Although grizzly populations have been slowly rising, "delisting would be disastrous," says Doug Honnold, an attorney for Earthjustice. "It could be the difference between having bears in Yellowstone and Glacier and not." Many biologists agree the bears are not fully recovered and contend that recent population gains would quickly be reversed if the bears are delisted.

This spring, when the grizzly exited its den to begin hunting, it found its life in order, but it could emerge next year to find its favorite hunting spot populated with oil derricks instead of young elk calves. CONTACT: U.S. Interagency Grizzly Bear Study Team, [phone], www.nrmsc.usgs.gov/research/ig bst-home.htm.