They had to destroy the forest to save it.

In a wilderness area on Holy Cross Ridge, just a snowball's throw west of this resort, 30 acres of trees have been gouged out of a lush pine stand, leaving a ragged, vacant scar.

The trees were cut down by order of the U.S. Forest Service, which has begun a major clear-cutting campaign in some of the most scenic sections of the Rocky Mountains.

The Forest Service is responding to a double-barreled problem. The pine forests of the western mountains have been hit this summer with the worst infestation in decades of a killer pest, the mountain pine beetle.

The mountain beetle and its Dixie cousin, the southern pine beetle, have ravaged hundreds of thousands of acres of forest in the West and Southeast. "We've got a major insect epidemic on our hands," said Hank Deutsch of the Forest Service regional office in Denver.

And this has come just when the Environmental Protection Agency has issued a ban on forest use of the traditional anti-beetle weapon, the chemical ethylene dibromide (EDB).

"Without EDB for beetle control, your only option boils down to vegetation management," said Dave Stark, the district forest ranger responsible for the Holy Cross Wilderness Area west of Vail.

"Vegetation management" is the foresters' term for cutting down trees.

The mountain pine beetles are attacking the lodgepole pine, a tall, straight tree about the diameter of a telephone pole that got its name because American Indians used the trunks as center poles for their teepees.

When the beetle lays its eggs in a lodgepole, the larva eat a circle around the trunk. "It's 100 percent effective," Deutsch said. "I mean, it kills that tree."

Summer tourists in the Rockies have reported that the normally verdant alpine forests are blotched with an ugly maroon, the color of dying lodgepole pines.

In addition to esthetic concerns, large swaths of dead trees could fuel forest fires. "If thousands of acres of our forest are dead, you might see what happened in Montana all over these mountains," Stark said.

The clear-cutting operation is designed to interrupt the geometric growth in the beetle population by eliminating millions of particularly susceptible trees. Once cut, the trees -- and the beetles in them -- are hauled away to a sawmill.

No one here seems to contest the Forest Service's decision to eliminate 10- to 40-acre patches of trees in the high country. But there have been questions about the decision to bring in logging companies to do it.

"Yes, there's a major insect problem in our forests this year," said Mike Scott of the Wilderness Society in Denver. "But is a massive logging operation the answer? They could burn the susceptible trees. They could just leave nature alone. But the Forest Service's basic instinct is to treat our forests as a crop to be sold."

Scott notes that the Forest Service has been under pressure from the president's Office of Management and Budget to make the forests more "productive" -- to generate more income for a deficit-plagued government.

But the pine-cutting operation comes at a time when lodgepole pine prices are so depressed that many sales of forest timber cost the government more in management than they earn in fees.

The clear-cutting decision has been accepted, although painfully, by Vail Associates, the corporation that runs the 10,000-acre resort here on land leased from the Forest Service near the center of the beetle infestation.

"Cutting down stands of trees here is an environmental and economic problem," said Joe Macy, the resort's technical manager. "The person who's riding the ski lift or sitting in his $600,000 condo doesn't want to look out and see a bare patch instead of forest."

But if the beetles are not controlled, Macy added, "We're looking at an economic disaster of the first magnitude. So do you have a choice? You probably have to cut trees down now if you want to have the forest around in a decade or so."