The uncontrolled fires that now blacken vast expanses of California countryside are a result of the great drought that has gripped the region - and officials fear they may be setting the stage for future years of more drought and fire.

Weary officials of the Inter-Agency Command Center here, coordinating the fire fighting efforts, said today that the fires, which have destroyed 250,000 acres of forest and grassland since July 25, are consuming valuable watershed that had been counted on to help the state recover this winter from the drought.

Vegetation on the steep hillsides preserves water and prevents erosion of the topsoil. With the vegetation gone, officials fear the hills are likely to erode - filling near-empty reservoirs with silt instead of water.

"There is a great risk of siltation," said Richard Serino, a spokesman for the U.S. Forest Service, "With the ground cover gone, we're going to have a problem in water quality."

The only bright spot from the standpoint of erosion control is that the fires have arrives so early. The Forest Service anticipates having time before the winter rains to reseed with grass and to build small diversion dams to prevent erosion.

Whether this is successful, Serino said, will depend on whether the rain falls gently, minimizing erosion, or arrives in a series of thunderstorms.

Thunderstorm lightning is what caused the two big fires that continue to blaze out of control.

The Marble Cone fire near Big Sur already has blackened more than 77,000 acres of Los Padres National Forest and the Vedanta Wilderness. The fire is only one third contained, and officials cannot estimate when it will be brought under control.

The other big fire, Scarface, in the northeastern corner of the state, was reported nearing control after destroying more than 80,000 acres. The smoke could be seen in Utah, 500 miles away.

Smaller fires in Oregon, Arizona and Nevada were near containment today. But fires continue to burn in Alaska, across 1.5 million acres of range and tundra in an area the size of Delaware.

The Big Salt fire, which once appeared to threaten the trans-Alaska oil pipeline north of the Yukon River, was described as "no longer a threat at all" by Kerry Carter, a spokesman for the Bureau of Land Management. Overall, Alaskan firefighters were aided by rain and cooler weather, Cartier said.

No such natural help was on the horizon in California.

Washington Post staff writer Cynthia Gorney, accompanying crews battling the Marbel Cone fire, filed this report from Flores Camp high atop a ridge overlooking the Pacific:

"As you come down the California coast toward Big Sur there is a point south of Pebble Beach where the fog doesn't feel right. Suddenly, you realize it's a combination of fog and smoke and catch the acrid smell of the burning.

"The Big Sun fire is in a steep, inaccessible area and it is hard for firefighters to find the fire they're battling. I heard one of them say he hadn't seen the fire in three days.

"Marble Cone started as two separate lightning-caused fires that met on smoke 14000 feet high. There are 3550 people battling it, using 57 engines, 31 bulldozers, 14 helicopters, seven air tankers and 12 ground tankers. It's like a war."

In an effort to win that war, fire-fighters from 47 states have been rushed here to join the 10,000 Californians already on the lines. The entire state is on "Manning Pattern C," the code words used by firefighting agencies to indicate that everyone is on duty.

Serino said supperssion costs already have topped $8 million and damage losses will be many times that. He also said the heavy loss of timer will generate pressure ofr increased cutting in other national forest.

As the drought already has, the fires remind the West that man's natural would is an interdependent one, where each supposed act of conservation has a consequence.

For instance, firefighting techniques have become so effective in recent years that underbrush has accumulated in the forsts - providing fuel for today's blazes. The underbrush has been a particular problem in Los Padres National Firest, portions of which had not suffered any fire since 1896.

In Arizona, officials are worried about heavy runoff when storms do come, because of the absence of ground cover. Also, Arizona's man-made defenses against fire are stretched thin, officials said, because 1,600 firefighters are on loan to California and the Northwest.

A series of lightning strikes, such as those that caused fires in Arizona and New Mexico earlier in the year, could force Arizona to borrow firefighters.

The shortage of firefighters is a factor in the size of the blazes. Myron Lee, managing the Marble Cone firefight, was forces to adopt a defensive strategy protecting the watersheds of Carmel and Monterey but, in Lee's words, "conceivably doubling the size of the fire.

Elsewhere in California, three of four big fires extending in a south-western are from Mt. Shasta to near the Nevada line were described as near containment. The exception was at Eagle's Lake, near Susanville, where 7,000 acres have burned. In Southern California, the Bonita fire continued to burn out of control near Sequoia National Park, after blackening 7,500 acres.

In Oregon firefighters were making headway against the Lost Fire, near the California border, which had burned 7,760 acres. Crews battled smaller fires in Oregon, Washington and Utah.

Fire danger warnings were up throughout the West. "No smoking" and "no charcoal fires" signs will be posted Wednesday in three major Arizona national forests. The signs have been in effect for weeks in California and the Northwest. One sign in Northern California read: "In Chicago a cow did it, in California people did it."

Actually, people have been responsible for few of the present crop of forest fires, because the danger is widely recognized and carelessness is dealt withe severely.

All the major fires now going in California were caused by lightning. When a target-shooter started a fire Sunday on the edge of the San Bernardino National Forest, he was immediately arrested on federal charges.

But every precaution may prove insufficient if California's long summer remains dry. The traditional month of greatest fire danger is September, when the dry Santa Ana winds in Southern California make fire containment a near impossibility.

Sighed and official in Sacramento today after reviewing himidity and temperature reports: "I hate to say it, but I fear the worst is yet to come."