UPUYER, Mont. - On the rolling prairie that rises up here to become the wall known as the Rocky Mountains a few miles away, Mark Taliaferro points toward the field where the carcass of a cow was recently found. "It is not a natural death," said Mr. Taliaferro, a cattleman who has been ranching in north- central Montana for more than 25 years. "When you see it, I tell you, it makes a believer out of you that something weird is going on."

Eight cow killings have been reported in Montana since June 12, the most recent on Aug. 31. And they all appear similar to the ones that occurred in the 1970's.

For ranchers and law enforcement officials in this remote part of Montana, the last few weeks have dredged up those memories. For several years the prairie country along the east front of mountains was rocked by dozens of cattle deaths in which the carcasses were mutilated. Some law enforcement officials and veterinarians who investigated said they had never seen anything like it.

"We had a bunch of them," said Pete Howard, the Choteau County justice of the peace, who was sheriff when the first mutilations hit their peak. "I've lived in this county all my life and worked on ranches and seen plenty of dead animals, but never did I see an animal with its face mask removed like that."

Brian Schweitzer, a cattle rancher near Whitefish, Mont., who was the unsuccessful Democratic candidate for the United States Senate last year, recently found one of his cows killed in the same inexplicable way as the others. "The brand inspector said it was lightning," Mr. Schweitzer said, "but there was no lightning that night. And it very much looked like those incisions were done with instruments. But I said fine, there's a lot of things I can't explain." Mr. Schweitzer valued the loss of one grown steer at about $850.

Now, as then, law enforcement officials and ranchers are split over whether the deaths merit investigation as anything more than a lightning strike or a wolf kill.

In all the cases, part of the animal's face, called the mask, is removed, along with reproductive organs. There is usually no blood, and predators will often not touch the carcass.

"This publicity is awful," said Leland P. Cade, who was editor of The Montana Farmer Stockman, a trade magazine, in the 70's and wrote four articles about the killings then. "City people don't know what's going on, and they envision crazy people doing weird things to animals in the night."

Law enforcement officials in the 1970's erred in thinking the deaths were mysterious, Mr. Cade said, although the cause was never determined. The cattle, he said, were probably killed by predators, who have been known to remove faces and organs. "Now we have a brand- new crop of ignorant people who don't know what goes on on the range," he said.

But Dan Campbell, who was raised on an area ranch and is now the Pondera County sheriff's deputy, says people who dismiss the deaths are not looking hard enough. No vehicle tracks or footprints have been found around the animals. Cuts made to remove the tissue are very clean. "There are smooth edges on those cuts," Mr. Campbell said. "They are not bite marks."

Part of the problem, investigators say, is that if someone accepts that these deaths are not run-of-the-mill, finding any way to explain them requires a long stretch of the imagination. The mystery and savagery of the deaths have led the more fanciful to speculate that the cattle, which can weigh nearly a ton, were killed by a band of satanic cultists, by U.F.O.'s or by secret military testing.

Keith Wolverton, a retired detective with the Cascade County sheriff's office, investigated 67 mutilation cases as the director of a five-county task force from 1974 to 1977. The mutilations are a real phenomenon, Mr. Wolverton said: "I don't think little green men have come from another planet to kill cows." Neither does he think the killings back then were the work of a cult, an angle he and other investigators pursued for a while. "Someone always talks," he says, adding that who did it and why is a question that still haunts him.

One organization that takes the killing seriously is the National Institute for Discovery Science, which is financed by Robert Bigelow, a real estate and aerospace mogul. With a team of six investigators that includes academic researchers and former law enforcement officials, the organization has studied cattle killings for six years. It receives six to eight reports a year, primarily from Western states and investigates the deaths with forensic techniques.

Colm Kelleher, a biochemist who is deputy administrator of the group, said the only thing research showed for sure was that "someone is cutting up the animals with sharp instruments, and chemical substances are sometimes added." One cow found dead in Utah had a hole in its head with the preservative BHT and formaldehyde in it.

Who might be doing it? "We don't know, and the last thing I would do is speculate," Mr. Kelleher said. "This field is full of speculation."

http://www.nytimes.com/2001/09/17/national/17COW.html?ex=1001304000&en=b26fa9347 4e7e51b&ei=5040&partner=MOREOVER