Gunfire echoed across Padgett's Field again today, the smoke from the Baltimore Light Artillery's six-pounder clinging to the sodden grass for a moment before the wind blew it into the woods.

Orders were shouted again, too. "Nine hundred yards!" yelled a man in a gray wool uniform, just as others had generations before. "Fire!" And the air shuddered from the explosion.

One hundred and thirty-seven years after Union and Confederate soldiers shelled each other in the fields and forests of South Mountain here, a group of government officials joined a band of reenactors to promote, among other things, the creation of Maryland's first Civil War battlefield state park.

Led by Comptroller William Donald Schaefer, who as governor was a vigorous advocate for Maryland Civil War sites, the group staged an emotional remembrance of the forgotten battle and also designated the remote battlefield a state "treasure of the month."

The site along the border of Frederick and Washington counties is in the westward path of development that is encroaching from bustling Frederick, and participants today said it is largely overshadowed by the National Park Service's Antietam National Battlefield about 10 miles away.

Indeed, the U.S. Department of the Interior has named South Mountain one of the most threatened Civil War battlefields in the country, according to Maryland 2000, the state's commission to celebrate the millennium.

Although part of the battle's site already is in state hands in the form of several state parks, the legislature resolved this year to study combining them into a state Civil War park by acquiring land or purchasing easements.

A 13-member gubernatorial task force is now studying the matter, with a mandate to report back to the governor by January. Many said today the situation is urgent.

The bulldozer, those in atten- dance warned, was approaching these pristine heights as inex- orably as the long columns of Union infantry did almost a century and a half ago.

"There's tremendous pressure to build on battlefields," Schaefer said. And "once it's paved over, once the houses are built, the memories are lost, history is lost, and I guess, in a way, love for our country is lost."

"You can get emotional just standing here," he said, as reenactors stood at ease nearby with rifles and bayonets.

Earlier, reenactor Doug Dobbs, 45, of Hagerstown, Md., had stood in the drizzle in a faded blue Union uniform and dark rain cape. He said he was worried.

"Look at Frederick County," he said. "It's blown wide open. Strip malls galore. Housing develop- ments. They're racing across the landscape faster than the cavalry.

"If you want condominiums at the bottom of the state park here, you can have that," he said. "What we're trying to do is to preserve the landscape so that our great- grandchildren can come here and say that it's on this mountain that your great-great-great-great-grand- father fought, and this is why."

As Dobbs, Schaefer and others spoke today, fog drifted among the dripping treetops, turkey buzzards soared on the mountain's updrafts and the steeples of the little town of Burkittsville looked much as they had in 1862.

The Battle of South Mountain often gets lost in the historical shuffle, experts said today. If events had unfolded differently, it might have marked the beginning of the end of the Civil War.

The battle was fought Sept. 14, 1862, a prelude to the much larger and bloodier battle of Antietam that unfolded three days later.

Confederate forces under Gen. Robert E. Lee were scattered west of the mountain in the South's disorganized first attempted to invade the North, 17 months into the war.

In a great stroke of military luck, Union soldiers the day before had found a lost copy of Lee's plans wrapped around three cigars and presented it to their commander, Gen. George B. McClellan. The ill-starred McClellan is said to have exclaimed: "Now I know what to do!"

Union forces went surging out of the camps around Frederick for the passes in the mountain to try to cut the Confederate forces in two, with mostly skeleton units of rebels barring the way.

It was a spectacular sight, one of grandest of the war, observers said, with columns of Yankees snaking for miles up the roads to battle for control of the summit. Once there, they fought the stubborn rebels over several gaps in the mountain, including Crampton's and its sloping Padgett's Field. But the Confederates held, the Yankees hesitated and the war raged on for almost three more years.

The battle's history includes several interesting footnotes.

Among those killed was Union Gen. Jesse L. Reno, for whom Washington's Fort Reno and Reno Road were named. Among the mid-level commanders was the profane colonel of the Union's 23d Ohio, future president Rutherford B. Hayes. The unit also had a supply sergeant named William McKinley who would go on to greater things.

None of this helped the Yankees, though. They got stalled at the top, until Lee gathered his army for the bloodbath at Antietam.

CAPTION: Union reenactors fire a salute during ceremony at War Correspondents Memorial at Gathland State Park, part of the South Mountain battlefield.