The decades that the U.S. Forest Service fought each and every wildfire have "essentially created a monster" by interrupting nature's way of preventing insect infestation and disease in national forests, a forestry expert said.

But the agency's new practice of allowing fires to burn in wilderness areas has drawn fire from a Boise man who watched the Deadwood Summit fire scorch much of the land around his wilderness ranch last year.Because of the Forest Service's success in suppressing forest fires, tree stands are becoming denser, said Michael Harrington, a research forester with the Forest Service's Intermountain Fire Science Laboratory in Missoula, Mont.

Because of the heavy growth, trees are growing poorly and becoming unhealthy, he said.

"They're not resistant to insects and disease. They're decaying and falling apart, and, in fact, we've created a worse fire hazard and (more) unproductive forest than we have in the past," he said.

Jack Gollaher, fire management officer with the Boise National Forest, agreed.

"We're finding out that, over time, we're creating some horrendous fuel loading, and we're not getting the proper mosaic in terms of the environment" because of firefighting, he said.

In Idaho, Western and Mountain Pine beetles have infested large stands of ponderosa and lodgepole pines. Experts said the infestation was caused, in part, by having dense stands of unhealthy trees.

The agency already allows wildfires to burn naturally in wilderness areas as long as they don't threaten structures or natural resources such as fisheries.

For example, in August 1987, the Forest Service let the Deadwood Summit fire in the Frank Church River of No Return Wilderness Area burn more than 63,000 acres. Firefighters intervened only when the blaze threatened resources or property.

Tom Allegrezza, owner of the Sulphur Creek Ranch, criticized the Forest Service for not fighting the fire and attempted to hire his own fire crews. He said the blaze damaged valuable elk habitat and streams, as well as his outfitting business.

"The policy to let fires burn is a little bit in question. I'm not opposed to letting fires burn. But you have to have some type of control," he said. "They shouldn't have let it burn in such a dry year. They should have had a goal of letting it burn 15,000 acres and then say, `OK, we're going to stop it here."

Harrington said it is too soon to let wildfires burn uncontrolled ouside of wilderness areas, under most circumstances.

"Because we have more trees, there's more fuel - needles, litter, underbranches - than there ever was before," he said. "So when we have a fire in these types of situations now, it's much more severe and much more damaging than it ever was in the past."

He said the Forest Service is starting to use controlled fires, called "prescribed burns," to clear out stagnant stands of trees.

Many national forest districts are beginning to designate regions outside wilderness areas where natural fires will be allowed to burn under certain conditions, he said.

Gollaher said the Boise National Forest views wildfires differently now.

"When we look at suppressing the fire now, we look at the cost of what we're really saving," he said. "We're not neccessarily going to put $4 million into a fire that's only going to destroy $250,000 of timber."