Reacting to months of grumbling from hunting, fishing and conservation groups, the Bush administration announced Tuesday that it is backing away from plans for gas drilling in Montana's Rocky Mountain Front, the only place in the West where grizzlies and bighorn sheep still come out of the mountains to wander on the Great Plains.

"We decided it would be inappropriate given the values that exist in the area," Rebecca W. Watson, assistant interior secretary for land and minerals management, said in an announcement made in Billings, Mont., not far from the Rocky Mountain Front -- a stunning landscape where the plains collide with steep mountains and where private, federal and state land abuts the largest cluster of wilderness in the Lower 48.

With the exception of buffalo, the Front remains prime habitat for all the big game that wowed the Lewis and Clark expedition as it passed through the region two centuries ago. The region has often been described as "America's Serengeti."

Watson acknowledged that the Bush administration had heard complaints about gas drilling in the Front from the "the hook and bullet crowd," a cluster of conservation groups, many of which represent wealthy sportsmen who often vote Republican. The Boone and Crockett Club, whose members include a number of wealthy Texas oilmen, owns a large ranch on the Front. "We listen when they talk to us," Watson said, adding that a final decision on drilling in the area will be put off until 2007.

The courting of hunters and anglers, whose numbers are huge in swing states such as Ohio and Pennsylvania, has become a significant part of the campaigns of President Bush and Sen. John F. Kerry (D-Mass.).

There are an estimated 50 million hunters and anglers, and their vote went mostly to Bush in the 2000 election, with gun rights as the decisive issue. But hunting and fishing groups became concerned last year that Bush administration policies on energy exploration and wetlands development were damaging prime hunting and fishing habitat.

Their concern registered with Bush, who in the past year has invited leaders of these groups to meet with him at the White House and at his ranch in Crawford, Tex.

"At our meeting in Crawford in April, the president said specifically that there are places where you ought not to drill," said James D. Range, chairman of the board of the Theodore Roosevelt Conservation Partnership, an umbrella organization for hunting and fishing groups. It has been hearing angry questions about Bush policies from sportsmen across the country.

In December, Bush met with Range and leaders of about 20 other conservation groups at the White House. They complained then about the Front and about a proposed plan to rewrite the Clean Water Act of 1972 in a way that could harm western wetlands and streams. Four days after that meeting, the wetlands plan was dropped.

"It seems the new constituency to court in this election season is the gun-rack pack," said Chris Wood, vice president for conservation at Trout Unlimited, a conservation group. "This decision on the Front demonstrates that Bush is listening. Let's hope it continues after November 2nd, whoever is in the White House."

Drilling on the Front was also immensely unpopular in Montana and across the Rocky Mountain West. The Wilderness Society recently released a report showing that of those who commented as part of a federal environmental impact statement on proposed drilling in the Front, 99 percent opposed it.

"I think the administration realized how important the Front is to Montanans and Americans," said Sen. Max Baucus (D-Mont.), who for years has fought energy exploration there.

According to federal figures, the amount of recoverable gas in the Front represents no more than a few days' worth of national gas consumption.

The administration also announced Tuesday that it plans to protect land in the Front by working with private groups to purchase conservation easements on 170,000 acres of ranchland.

A whitetailed deer crosses a road in front of Montana's Rocky Mountain Front, which remains prime habitat for big game.