GROVELAND, Calif. — As the massive Rim fire roared out of the Stanislaus National Forest and deeper into Yosemite National Park this week, public attention rose sharply.

But the intensity of firefighting did not.

That’s because part of the blaze had crossed into the jurisdiction of the National Park Service, which has a more restrained approach to managing wildfires than other federal, state and local fire agencies battling the 300-square-mile blaze.

Officials estimate that it will be fully contained in two or three weeks, but it is expected to keep smoldering for weeks longer and won’t be truly out for months.

“This fire will burn until the first rains or until the snow flies,” said Lee Bentley, a spokesman for the U.S. Forest Service.

Although the 4,900 firefighters here operate under a unified command, the park service has a very different firefighting philosophy from that of the forest service or the California Department of Forestry and Fire Protection.

The portion of the Rim fire burning outside the park is fought aggressively by the forest service and Cal Fire.

Bulldozers rip fire lines across the landscape, and crews fell trees and set protective backfires. Helicopters and tanker airplanes drop water and retardant.

“We want to send as much equipment to a fire as we can,” said Cal Fire spokesman Daniel Berlant. “Our goal is to put it out early and avoid having a large fire.”

But inside parks, a policy often called “fire use” accepts fire as a naturally occurring process and often a useful tool.

Park fire managers suppress blazes that endanger people or threaten structures and resources. Fires in tourist-heavy Yosemite Valley, for instance, are “very, very controlled,” said Tom Medema, Yosemite’s chief of interpretation and education.

Otherwise, park officials prefer to herd fires where they want them to go and allow blazes to burn out on their own.

It’s a science-based approach that serves the same function as off-season forest thinning and controlled burns. But those arguments often fail to stand up to public distaste for trees burning in beloved national parks.

“People will say, ‘I’ve planned my whole life for a trip to Yosemite and I can’t even see Half Dome,’” Medema said. “I totally understand that.”

Public perception is fed by a belief widely held in the 1940s, ’50s and ’60s that fire is bad, period. The park service has worked hard to change that perception, and Medema said the agency has made progress.

As the Rim Fire invades Yosemite, park officials will pore over maps that reflect the historic fire return interval — the frequency that natural fire goes through an area. Every acre of the park is mapped in this fashion, and each has a fire “prescription.”

So, for instance, when the blaze hits an area of the park where fire returns every 12 years — but hasn’t been burned in 16 years — the prescription for that area is to let it burn.

The park service’s distinction between natural and human-caused fires is not one that other agencies make. “It doesn’t matter how the fire started. We are going to suppress it and put it out,” Berlant said.

Jumping on fires quickly makes sense given Cal Fire’s mandate. The state agency protects 31 million acres of mostly private land and millions of acres of forests owned by timber companies, and it has the responsibility of protecting hundreds of small communities from wildfires.

Cal Fire’s muscular response to fire is reflected in its arsenal: It has the largest fleet of firefighting aircraft in the world and owns 23 large tankers. In comparison, the federal government has nine tanker aircraft on contract.

It is not likely that anyone will allow the Rim Fire to consume Yosemite in the manner that catastrophic fires ravaged Yellowstone National Park in 1988, the precursor to today’s era of mega-fires. About 706,000 acres in Yellowstone burned, or just under a third of the park. Before those blazes, the biggest known fire in Yellowstone was one in 1886 that burned out after destroying 25,000 acres.

The Yellowstone fires in 1988, most of which were touched off by lightning, began in June on a landscape hollowed out by drought. Park officials monitored the complex of fires and allowed them to burn unimpeded through the park for nearly a month. Haze from the fires reached the Midwest.

Amid mounting criticism, park officials patiently explained the agency’s “let it burn” approach, to little avail.

“In the national parks, a major part of our job is to protect a place so that nature can work,” Yellowstone spokesman Al Nash said this week. “In many large parks in the West, fire is one way that nature works.”

But the park’s trial by fire brought about a re-examination. “It prompted everyone to step back and look at their approach,” Nash said.

Eventually, the Yellowstone fires required 25,000 personnel, including two battalions of Marines, and more than 10 million gallons of water.

The last flame was extinguished in mid-November 1988 — by rain and snow. The cost of the five-month firefighting effort came to $120 million.

And despite the arm-waving about the park service’s seemingly laissez-faire approach to fires, the policy remains in place.

But don’t expect to hear any park service employee utter “let it burn” again.

“Those are certainly three words you will never hear me say,” Nash said.