WASHINGTON (AP) -- Hunters eventually could be allowed to kill grizzly bears in three states if the government is successful in removing federal protections.Grizzly bears in and around Yellowstone National Park had dwindled to 220 to 320 animals in 1975, when they were listed as a threatened species under the Endangered Species Act. In the past 30 years, the Interior Department says, the number of bears in that region has grown at a rate of 4 percent to 7 percent a year, and they now number about 600.Because of this rate of recovery, the department on Tuesday proposed taking the grizzlies off the list.Removing federal protection would allow Wyoming, Montana and Idaho to assume management responsibilities from the federal government for grizzlies around Yellowstone, and state plans leave open the possibility of limited grizzly bear hunting. Bears within Yellowstone and Grand Teton national park would remain off limits to hunting, however.Environmental groups are split over the issue. The National Wildlife Federation supports ending the protections, saying it would highlight the success of the endangered species law. But the Natural Resources Defense Council, the Sierra Club and other groups contend the grizzly should remain on the list because too many threats to the animal still exist. They include oil and gas drilling, logging and the growing number of housing developments.Republican lawmakers say the success of recovering the bears is a rarity under an endangered species law that is ineffective and burdensome to landowners. Fewer than 20 species have been recovered since President Nixon signed the law in 1973.Many in Congress have called the law a failure, and the House passed a bill in September to lessen the government's role in managing species."The fact that we are rolling this out with such fanfare underscores what a rarity recovering a species is," said Sen. Larry Craig, R-Idaho. "It is a testament to the partnerships created in this case, but also a cry for reform of the ESA."Interior Secretary Gale Norton said Tuesday that grizzly bear recovery has been a success because of cooperation between state and federal governments, along with biologists and conservation groups. She added, though, that the Bush Administration would like to see the law focused more on recovery efforts than on penalizing landowners who find endangered species on their land.Four other grizzly populations in the lower 48 states will continue to be protected as threatened species under the act. These bears live in the Montana, Wyoming, Idaho and Washington. Alaskan grizzly bears, which number about 30,000, were never listed.Norton said Yellowstone grizzlies could be removed from the list as early as 2006, but acknowledged that litigation could delay the move.Copyright 2005 The Associated Press. All rights reserved.This material may not be published, broadcast, rewritten, or redistributed.