Experts say forgotten burial plots dot Central Ohio, lurking silently beneath your feet.

First, workers found a human collarbone. Then, near the sliver of calcium encased in rubble, someone's ribs and arm bone appeared.

Eventually 25 sets of human bones were uncovered during excavation to put sewer lines near the North Market in 2001 -- remnants of the old North Graveyard, located in the Short North from 1813 to 1873. Most of the bodies had been moved to make way for neighborhood improvements, but others were left behind.

Those unlucky deceased are not alone: Experts say forgotten burial plots dot Central Ohio, lurking silently beneath your feet.

"People have been here for 10,000 years or more, so their deceased relatives have to be someplace," said Bill Pickard, assistant curator of archaeology for the Ohio Historic Preservation Office.

The simple math of generations -- millions of people, thousands of cemetery plots -- means you've likely passed over history interred.

Take Downtown, site of an ancient burial earthwork fashioned by the Hopewell mound builders. Archaeological digs before the construction of the new Franklin County Courthouse yielded no human remains, but remnants might have been removed from the Mound Street mound along with clay used to build the first Ohio Statehouse.

Years later, pioneers traveled to places like Sharon Township, farmed and died. The Overlook Trail at Highbanks Metro Park wanders past the headstones of the Pool Family, a settler couple and their 11 children whose gravestones were arranged by park staff as a tribute in 1981.

The bodies were never found.

"Ohio does a good job with documenting historical cemeteries," said Michael Krakovsky, an archaeologist with Hardlines Design Company, based in Columbus. "They have resources we can access to find out where cemeteries were or might've been, even if there are no headstones or marked spots."

In his two years of work, he's found human remains at only one dig -- a centuries-old military fort in Manhattan's Battery Park.

Still, graveyards were plotted since settlers founded Franklinton in 1797. But reliable burial documents in Ohio, experts say, date back only to the Civil War.

Cemeteries since then have been moved hastily for commercial development, railroads, government projects and, sometimes, just for convenience, said Lolita Guthrie, an official with the Ohio Genealogical Society.

"When people bought property, they would find stones and remove them," she said, recalling an Ohio woman who uprooted a few stone markers, wheeled them out back and used them as steps to her chicken coop.

Weather, time and the wheels of progress also take their toll on the hidden places of eternal rest. Tombstones crumble, plots erode, and graves often fall from sight and memory. Often the graves of blacks, orphans, prisoners, asylum detainees and the poor were never marked or recorded.

About a dozen new cemeteries are found each year, mostly on private land, left decaying in secret, Guthrie said. Names and stories usually are long gone, even if skeletons and spirits linger.

"Even with better records, [cemeteries] can pop up where you least expect them," Guthrie said. "It's an unending process."

Digging It

Your fall cleanup is going fine until you rake up a human hand. Now what? Here's what archaeological experts suggest doing if you find remains on your property.

Contact the police: Local authorities need to make sure the uncovered remains don't belong to someone in an ongoing investigation. Usually, the coroner handles things.

Survey the scene: Digs are much like crime scenes, so don't disturb the remains or the surrounding area until authorities are finished studying them.

Get help: If the remains aren't part of a current case, private or public archaeologists might be interested. Private companies charge excavation fees, but the site could pique the interest of a university professor or preservation official who may come out for free.

Cover it up: Archaeologists might take more peculiar items back for study. The rest can be reburied at the discretion of the landowner.