On a bleak midnight last December, the frozen carcass of a dead timber wolf was left on the steps of a U.S. Park Service headquarters north of here. The wolf had been shot in the head and, painted on its mangy hide in large white letters was the inscription: S.O.S.

Killing a wolf, which is an endangered species protected by federal law, carries a maximum penalty of $20,000 and a year in prison. But in a letter claiming responsibility, an anonymous group called "Sportmen's Only Salvation" threatened to kill severeal more.

A few weeks later, a wolf's severed head was found on a stairway of the Duluth News-Tribune. Another carcass was left on the doorstep of the Tower, Minn., city hall.

The protest served notice on the federal government that unless something is done about the woves around here - and quickly - Minnesotans would take the law into their hands.

Since the wolf became protected under the Endangered Species Act three years ago, federal officials say, its population has almost doubled in Minnesota, the only state outside of Alaska with significant numbers of wolves. In the last year, the wolf has ranged far outside its traditional northeastern Minnesota territory, attacking dongs, devouring cattle and scaring people halfway down the state.

"We have a mad public," said Jack Hemphill, regional director of the Interior Department's Fish and Widlife Service. "There are too damn many conflicts with man. Something has got to change:'

What Interior proposes is to recalsify Minnisota's 1,200 gray wolvesfrom their official "endangered" status to a "threatened"status which would allow limited killing in certain populated areas. Wolves would remain on the endangered list in the rest of the continental United States.

The plan, announced several weeks ago, satisfies neither state officials who want to handle wolves without federal interference, nor certain conservationists who oppose any wolf killing, nor hunters from groups like S.O.S. who would return to the days of the bounty, nor farmers who want to shoot any wolves that trepass on their land.

The conflicts cut deeper than ordinary politics, perhaps because of the wolf's mythic place in human history. "The fear of the wolf is ingrained in our subconscious." Hemphill said. "The Bible is full of wolf stories. Children are taught to be afraid of the wolf with tales like Little Red Riding Hood and the Three Little Pigs."

But if the wolf has inspired hatred over the centuries, it has, in the last decade, acquired the fierce loyalty of environmentalists. "The wolf embodies the spirit of the wilderness," says Karlyn Berg, a Minnesota conservationist who lives with four. "It plays a vital role in the balance of nature. By preying on inferior animals, the wolf prevents overpopulation and starvation among deer and moose.

Such sentiments weigh little with Julian Brzoznowski, 37, who farms 300 acres outside the small town of Orr. Three weeks ago, woves slipped into his pasture and slaughtered two calves. "All I found was a leg off one and a hoof off the other," he said.

Brzoznowski, who has lost 28 cattle to wolves in the last three years, has filed suit against the Interior Department for $58,000. "I want to protect my rights," he said. "But I'm not sure I have any. If I see a wolf eating my cow. I can't shoot it, or they'd arrest me."

Fish and Wildlife officers have trapped 35 wolves on Brzoznowski's farm. Most are released only 20 miles away, in the Superior National Forest. If they are not killed there by rival wolves, they find their way back to farmers' pastures. Brzoznowski said. One wolf, radio-collared by researchers, traveled 1,500 miles in 90 days.

From 1849 until 1965, the stare paid a bounty for dead wolves. Trappers could earn $35 a head "so the wolves were afraid of man," Brzoznowski said. "But now they've lost their natural enemy-and their fear.

"We've been farming here since 1920 and we never had a loss until 1974. Now they come howling around the house and my kids are so scared they can't sleep."

Brzoznowski has been hit the worst, but dozens of northen Minnesota farmers have lost cattle, geese and sheep to the wolves. The state legislature recently passed a bill to compensate them.

Environmentalists contend the losses are exaggerated and that farmers are "asking for wolf trouble" by cultivating land near the northern woods. "Agriculture doesn't belong there." said Toby Cooper of the Defenders of Wildlife which opposes reclassification of the wolf. "They're asking for a subsidy at the expense of the natural wildlife system."

If the wolves like cattle, gods, says the Fish and Wildlife Service's Hemphill. "are like ice cream to them. The Service gets weekly complaints from people who were walking in the woods and have had wolves come right up and take the dogs off their leash. Those people are mad . . . and hysterical."

Cooper calls such accounts "nonsense . . . The dogs go yapping after the wolves, so naturally they get killed."

In the most publicized incident, John Pahula, a retired miner in Soudan, Minn., was walking with his little dog, Pedro, last November, when two wolves approached within 60 feet. Pedro chased the wolves into the forest. The next morning, Pahula recalled, "all that was left was the collar and a few headbones.He was a brave dog".

The wolf's most vociferous enemies are Minnesota's hunters and trappers. "You have to understand that there are 300,000 hunters in Minnesota," Hemphill said. "But there are only about 60,000 deer."

The deer population has nose-dived in recent years from a high of over a million in the 1960s. Although hunters blame wolves, wildlife experts say the deer were artifically high 10 years ago and have declined because of changes in forest growth and excessive human poaching.

Arvid Haurunen, a retired trapper who heads the 2,000-member Virginia, Minn., Sportsmen's Club, says. "There aren't enough deer for the wolves and the hunters too." A good wolf hide, he adds is worth $300 hung on the wall or used for parka trim. "Let the citizen trapper make that revenue."

To Haurunen, environmentalists are "a bunch of pink-cheeked city kids who run 40 miles an hour if they ever saw a wolf."

In fact, wolf fans in other states may have abetter chance of seeing the predator if the Interior Department carries out its Eastern Timber Wolf Recovery Plan. The two-year study by eight wildlife professionals recommends that the wolf be reintroduced into Northern Michigan and Wiscousin.

Reintroduction sites in the Appalachian wildernesses should also be studied, the plan says, including the George Washington National Forest in Virginia and West Virginia, the Southern Appalachians on the North Carolina-Tennessee border, the Adirondacks in New York, the White Mountain National Forest in New Hampshire and two Northern Maine areas.

"The Eastern Timber Wolf once range over most of the U.S. east of the Mississippi," said environmentalist Cooper. "Obviously we can't have wolves in Central Ohio now, but a few places should be recolonized" to ensure a healthy wolf population.

The political obstacles are likely to be immense, judging by recent experience. When four wolves were transplanted to Michigan's Upper Peninsula two years ago, deer hunters formed a "Baraga County Wolf Hunters Association" offering a $100 reward per wolf. Three were shot and the fourth was run over by a car.

Eastern wildlife officials are skeptical of reintroduction efforts and the Interior Department seems to be in no hurry. "I think you'd start getting into philosophical problems real quick," Hemphill said.