As grizzly bears emerge from their dens in and around Yellowstone National Park this spring, they’ll no longer be protected under the Endangered Species Act.

The U.S. Fish and Wildlife Service announced Thursday that it plans to formally take the grizzlies in the greater Yellowstone Park area off the list of endangered species, with a posting of that decision on the Federal Register on March 29 and delisting to follow 30 days later.

The change probably won’t be apparent to the bears, noted Chris Servheen, who has worked on the survival of the species for 23 years.

“The majority come out of hibernation in April, and by the end of April they will be off the list,” said Servheen, the U.S. Fish and Wildlife Service grizzly bear recovery project coordinator. “But from the point of view of the bear, they will not see much difference.”

Removing the Yellowstone grizzlies from the list was lauded as a success story during a conference call Thursday with representatives of various agencies and conservation groups involved in the bears’ recovery.

“This isn’t only a serious occasion, but an occasion to celebrate the success of the Endangered Species Act and the effort to recover grizzly bear populations,” said Doug Inkley, a senior scientist with the National Wildlife Federation.

Joel Holtrop, deputy chief of the U.S. National Forest System, added that Thursday’s announcement was “decades in the making.”

When the Lewis and Clark Expedition passed through Montana in the early 1800s, more than 50,000 grizzly bears roamed from the Pacific Ocean to the Great Plains.

But as the area was settled by pioneers, the grizzly bear population decreased dramatically. In 1975 the U.S. Fish and Wildlife Service listed the grizzly bear as a threatened species in the Lower 48 States under the Endangered Species Act, placing the species under federal protection.

In the ensuing 30 years, the Yellowstone grizzly population has increased from 136 to 312 animals when they were listed in 1975 to more than 500 bears today, according to government officials.

Four other distinct grizzly bear populations exist outside of Yellowstone, mainly along the U.S. Canadian border. Those include about 500 in the Glacier Park/Bob Marshall Wilderness Area; 30 to 40 in the Cabinet/Yaak area; 30 to 40 in the northern Idaho and northeast Washington; and about five in the North Cascades.

Those remain protected as threatened species under the Endangered Species Act.

“The bears have dual citizenship and we work cooperatively with the Canadians along the border,” Holtrop said. “We’ll continue to try to minimize bear/human conflicts through outreach and education.

“… We’ll also continue trying to link some of those populations, because that makes them much stronger and healthier.”

The Interior Department said in 2005 that it intended to delist grizzly bears around Yellowstone National Park, but some environmental groups have said the move is premature.

“Just like polar bears, grizzly bears are threatened by global warming,” Earthjustice attorney Doug Honnold said. “They live in a world of shrinking habitat due to warming weather. The Fish and Wildlife Service didn’t see global warming coming and has no game plan for the loss of whitebark pines and the related harm to grizzlies.”

Michael Garrity, executive director of the Alliance for the Wild Rockies, added that the grizzlies were listed as a population based on their entire numbers, and he doesn’t think the protection should be removed until all the populations are connected through travel corridors.

“Conservation biologists have told us that to survive in the long-term, populations have to be connected to the other populations,” Garrity said.

Servheen notes that even with delisting, Yellowstone grizzly bear populations will continue to be closely watched. Those duties will be handled inside Yellowstone Park by the National Park Service. Outside the park’s boundaries, management activities will be taken over by state officials, at an estimated cost of about $3.7 million annually.

Deputy Interior Secretary Lynn Scarlett said her agency has earmarked $1 million per year in 2007 and 2008 to help states cover the management costs.

“Eventually, we’ll transition from the Fish and Wildlife Service to each of the agencies who will be implementing the conservation strategies,” Scarlett said.

Delisting eventually could result in a grizzly bear hunting season, but officials said they don’t have any plans for that at this point.

The Associated Press contributed to this report.

Reporter Eve Byron can be reached at 447-4076 or by e-mail at eve.byron@helenair.com