The government ordered as many as 1,000 regular Army troops from Fort Lewis, Wash., and Fort Ord, Calif., into firefighting duty yesterday to battle the storm of forest fires in the West.

Fires stretch 1,000 miles from Washington to Southern California's Mojave Desert, and the largest single fire covers an area twice the size of the District of Columbia. The blazes cover nearly 680 square miles in seven states, including: About 375,000 acres in California, where $20 million worth of timber has been destroyed and 12 of the state's 17 national forests have been charred. More than 6,000 Californians have fled blazes threatening their homes. From 75,000 to 82,600 acres in Oregon, where 3,000 people have been evacuated from their homes. Between 26,000 and 31,000 acres in Idaho, in addition to smaller fires in Arizona, Nevada, Washington state and Wyoming.

Dale Robertson, chief of the U.S. Forest Service, said the service has been flooded with calls from citizens volunteering to join the 700 crews, totaling 18,000 to 20,000 firefighters, on the scorched fire lines. But, he said, their assistance is being turned down.

So many professional firefighters have joined the effort out West that rangers in other parts of the nation are worried.

"We are concerned about fires at the present time because we do have manpower sent West, and it leaves us a little skimpy if anything happens here," said Larry Hakel, chief park ranger for Virginia's Shenandoah National Forest. "If we have any fire that gets over 100 acres, it would be beyond our capabilities."