COLD SPRING

No one knows what the shovel's last task was or who thrust it into the pile of sand. But there it stood for almost a century as forest erased the West Point Foundry in Cold Spring. That is until last week.

A stub of the handle remained, the straight blade still buried in sand probably last used to cast sugar production machines. Decades earlier, the sand would have molded cannons that powered the Union's Civil War win.

The sand and shovel were among ruins hidden in the woods below Route 9D - 87 acres worth of secrets found nowhere else.

"This really is the last place in terms of looking into 19th-century ordnance production," Elizabeth Norris, an assistant archaeologist with Michigan Technological University's industrial archaeology department, said this week.

She is part of the university's sixth summer of research in Cold Spring, including two public tours of the excavation starting today.

Students scraping away the layers of soil now covering the remains of the foundry's moulding shop found the shovel. Molten iron was poured into sand molds inside the shop to form the Parrot gun - the foundry's most famous product and a process illustrated in Jonathan F. Weir's 1866 painting "The Gun Foundry."

"There's an incredible amount of human history here," Joe Kiernan of Scenic Hudson said of the site, which is on the National Register of Historic Places. "We needed Michigan Tech to bring the stories to life."

The Poughkeepsie-based environmental group bought the foundry in 1996, 85 years after it closed. Plans include an interpretive park explaining how the foundry's location near sources of iron ore, wood for charcoal and water for power made it the premier ironworks of its day and a central player in the country's military and industrial history.

The need for a steady and reliable supply of cannons and other ordnance led President Madison to propose four sites for foundries capable of producing war material. Sprawling suburbia or conversion to other uses consumed the ones in Pittsburgh; Richmond, Va.; and Georgetown, now part of Washington, D.C.

Cold Spring resident Gouverneur Kemble, a diplomat and industrialist, built the West Point Foundry in 1817. By the end of the Civil War, it had produced millions of shells and nearly 2,000 cannons, probably all of which test-fired at least one shell across the Hudson. Under the direction of Robert Parrott, a West Point graduate, the foundry manufactured rifled cannons that came to bear his name.

Grooves inside the barrel caused shells to spin as they flew toward the target, improving range and accuracy. At its peak operation, about 1,000 men worked around the clock amid the heat, the smoke and the banging.

"Below us we could hear the deep breathing of furnaces, and the sullen, monotonous pulsations of trip-hammers, busily at work at the West Point Foundry, the most extensive and complete of the iron-works of the United States," historian Benson J. Lossing wrote in his book "The Hudson From the Wilderness to the Sea," published in 1866.

On Wednesday, a turkey vulture's shadow slid over the moulding shop's ruins. Teams of students excavated various areas near what was the doorway but is now where 90-year-old maple and sycamore trees grow. The air horns on Metro-North trains and soil rattling into a plastic bucket have replaced the roar of furnaces and the hammer's clang.

"People, I think, are very proud of this history and aware of it," said Mindy Krazmien, executive director of the Putnam County Historical Society and Foundry School Museum. The museum's small building at the head of the foundry's gorge is where apprentices and employees' children attended school. It's now the first stop for many interested in the foundry's past. Visitors, Krazmien said, come from across the country.

"So much of the information we can provide to people has come from the work Michigan Tech and Scenic Hudson have done," she said.

Past summers of study have included mapping the ruins and examining the water system. Along with the shovel, students in recent days have found nails, washers, iron scraps, smoking pipes, several metal files and an animal bone from someone's lunch.

The archaeology effort is critical to explaining the foundry's role in the village and the nation. Soil, trees and rubble still cloak many of those secrets.

"We need to give people an idea of what happened," Scenic Hudson's Kiernan said, gazing around the site. "I don't know if there's ever really going to be an endpoint."