Harsh winter weather and the effect of last summer's fires on winter range are resulting in earlier than usual elk deaths in Yellowstone National Park, a park spokeswoman said.

Joan Anzelmo said observations by federal and Montana wildlife experts support the theory that natural elk deaths are coming early this winter.For the past seven winters, which were all mild, elk mortality averaged 10 percent, she said. The elk population on the park's northern range has steadily climbed to its current level of about 19,000. Research has shown that the long-term capacity of the range is about 15,000 elk.

Although no official elk death count is available, Anzelmo said, "certainly we're going to have higher mortality." She said the prediction is based on elk overpopulation and other factors.

Heavy elk mortality usually starts in the spring, but Anzelmo said the deaths have already begun this year. About 140 elk carcasses have been counted in the park since Jan. 1. Park and Montana biologists have also reported that animals are in a weakened condition this winter.

"(Experts) are surprised at the kind of (elk) cows they are seeing taken by hunters," Anzelmo said. "They're old, without teeth, very thin. . . . These animals should not have been surviving each year, and they only did on borrowed time because of the mild winters."

She said public awareness of high mortality has been particularly high this year because animal deaths are occurring in large numbers at the peak of winter tourism in the park.

"This is our busiest (winter) month, and typically the mortality we see every winter - and there is mortality every winter - we don't begin to see it in a large way until March," she said. "This year everything is about a month early."

The accelerated timetable began last August when animals moved from summer to winter range a month early, Anzelmo said. The animals have now depleted their winter range.

"This is not a zoo. It's a national park, where the death of one animal means life to another," said park superintendent Bob Barbee in a news release. "Elk that are weak or dying in the spring will help get the new crop of grizzly cubs off to a good start in life."

Despite the high animal mortality, park officials said they concur with other state and federal agencies in opposing any supplemental feeding program for the park's elk herds. Officials said such programs work against maintaining natural ecosystems, are unlikely to be effective and are costly.