On an exquisite Sunday morning, David R. Doyle, surveyor, crouched low and peered into the nation's past: It was a small, stubby monument of sandstone, set down in what was wilderness 198 autumns ago, but what is now a front yard near an intersection in Takoma Park.

So weathered was the stone that its chiseled lettering was faint in spots. But this much was visible on one of the four sides: "Jurisdiction of the United States, Miles 2." And this on the opposite side: "Maryland." And the first three numerals of a date on a third: "179."

It marked a boundary. Thirty-nine others had been erected in the forests of Maryland and Virginia nearly two centuries ago, each a mile from the next and arrayed in a square with 10-mile sides. When the last stone was lodged, an infant nation had carved from two of its states a unique place under the "jurisdiction of the United States," a capital area to be called the District of Columbia.

"People come to Washington to see monuments, the Washington Monument and all that," Doyle had said earlier as he prepared to resurvey the marker at Maple Avenue and Carroll Street in Takoma Park. "But they never see these-and these were the first."

Remarkably, nearly all of them remain to be seen.

Despite the comings and goings of millions of people since the last decade of the 18th century, despite the advent of malls and subdivisions and roads and apartment buildings and stores, despite storms and falling trees and traffic accidents, at least 36 of the original markers have made it to the District's Bicentennial celebration, which will hit full stride next year. Three markers are missing and a fourth might not be an original.

It is in honor of the Bicentennial that Doyle and other volunteers have set out to repeat the work of the original surveyors and provide precise map coordinates for each of the remaining markers, now found along streets, in lawns, on property lines.

Some still mark the boundary of the District and Maryland. Some are now mere oddities surrounded by Virginia, because the portion of the District that was carved from the Old Dominion was returned to its control in 1846. But all the markers are apparently historical orphans, under no agency's routine care. Only the Daughters of the American Revolution have tried over the years to protect them, having put iron cages around many of them and now advocating that the markers be given landmark status.

"It's not kept up by anyone," Desiree Magney said yesterday of the marker on the fringes of her driveway on the Montgomery County-District border. "We go out occasionally and pull weeds from it."

"It's just amazing someone didn't dig it up and throw it in the trash," said Teri Ruddy, who lives on the Maryland side of Western Avenue and whose front yard bears two pine trees and, between them, one of the 2-foot-tall, square-foot sandstone markers.

Two men led the team that put them there.

On Jan. 24, 1791, President George Washington ordered that mapping work begin on territory on both sides of the Potomac River that would become the federal seat. Andrew Ellicott, of Philadelphia, who already had mapped Pennsylvania's northern and western borders, got the job. And he chose an unusual man to help: Benjamin F. Banneker, a free black man who was a math whiz and self-taught in astronomy.

For two years, the team slashed through forests, cutting a 40-foot-wide path through the trees to clearly delineate the border and provide a path for wagons and other equipment, said Michael G. Shackelford, chairman of the resurveying project. Every mile, the team implanted a marker. Every 10 miles, the team turned 90 degrees so that a square had been laid out when they finished.

The resurvey, which is being done by a committee of the American Congress on Surveying and Mapping, is financed by $90,000 in private donations and is strictly high-tech. To compute the location of the Takoma Park marker Sunday, Doyle, who works for the National Geodetic Survey in Rockville, used a small, $40,000 receiver to pick up satellite signals that, when fed into a portable computer, provided exact longitude and latitude.

When the team is finished and the locations of the markers are connected on a map, there is little doubt modern science will have found that the 18th-century markers do not form 10-mile-long straight lines on each side, Doyle said.

Instead, they could vary several feet from perfection, either because markers have been moved to make way for some project or because they were placed incorrectly from the outset. Either way, though, it is unlikely any deviations from a true line would lead to adjustments between the District and Maryland because "the boundary has been accepted" for so long, Doyle said.

At each location, the team plants a round, bronze commemorative disk in the ground that will provide an exact point of reference for anyone who needs one for modern-day purposes.

"These were very rugged men who did this," Shackelford said. "It just gives me a deeper appreciation of what they had to do to establish the borders of the nation's capital."