In 1832, a towering brick furnace burns at the edge of a swamp. Molten iron pours from spouts in its base. At the top, orange flames rise from the chimneys 24 hours a day. The light can be seen for miles.

Alongside the chimneys is the tunnel head, an access hole that plummets to the roaring belly of the furnace. Here, workers “charge” the furnace with three critical ingredients: iron ore, charcoal and oyster shells.

The furnace burns continually for 32 weeks of the year, pausing only for the coldest weeks of winter.

Now, let’s do the math.

A typical charge uses 500 pounds of iron ore, 40 pounds of oyster shells and 25 bushels of charcoal.

Workers charge the furnace every two to four hours, night and day.

By the close of the year, the furnace will consume up to 1.3 million pounds of iron ore, more than 100,000 pounds of oyster shells and 67,000 bushels of charcoal—all of the latter produced from timber harvested on site.

Every week, boats haul away 22 tons of pig iron for markets in Baltimore, Philadelphia and New York. In the 1800s, iron permeates nearly every daily task, a ubiquitous presence in tools, hardware, stoves, cookware and horseshoes. And, increasingly, it forges rails for the “iron horse” that connects a growing United States.

This particular furnace, located along Nassawango Creek on Maryland’s Eastern Shore, blasted for 20 years, at various levels of production, until final bankruptcy in 1850.

The same landscape today, now the Furnace Town Living Heritage Museum and The Nature Conservancy Nassawango Preserve, is testimony to the power of resilience.

And, the staggering amount of resources needed to sustain this production is testimony to the historic abundance in the Chesapeake Bay ecosystem.

The Furnace Town Living Heritage Museum and The Nature Conservancy Nassawango Preserve, members of the Chesapeake Bay Gateways Network, sit just south of Salisbury, MD. A thickly wooded glen shelters a variety of 19th century buildings reminiscent of the village that once thrived on this site.

The lush, tranquil setting provides a remarkable contrast to past history. At its center, the original iron furnace rises in a dramatic clearing at the end of a great “charging ramp,” an irresistible wooded promenade that lifts visitors eye-level with the chimneys.

Near the base of the furnace, the Paul Leifer Nature Trail begins a one-mile excursion into forested swampland that has been called one of the last true pieces of wilderness on the East Coast. This tract provided most of the resources that powered the Nassawango furnace for two decades. Today, bald cypress trees—mixed with oak, holly, sweet gum and maple—rise skyward and push their signature “knees” up from the wet forest floor.

These woods are also thick with undergrowth and wildlife, including 15 types of orchids and 14 species of nesting warblers.

Furnace Town is owned and operated by the Furnace Town Foundation, a homegrown organization of Worcester County. The Nature Conservancy, a national organization with extensive holdings along Nassawango Creek, owns the nature preserve. The Furnace Town Foundation provides on-site staff and protected access to the nature trail, while the Nature Conservancy enriches exhibits on the area’s ecosystem and connection to the Chesapeake.

It’s an effective partnership, if not an inevitable one, because neither story would be complete without the other. For visitors, it’s a seamless experience that weds the wonders of the Chesapeake ecosystem with both local and national history.

“This was pristine forest,” explained Kathy Fisher, executive director of Furnace Town. “But from 1820 to 1850, it was an industrial site, where they clear-cut 5,000 acres and built a canal. It was an intrusive industry that would never be permitted today, but back then it was simply economic opportunity.”

Walking the Paul Leifer Nature Trail, the tiny catalyst of this industrial activity surrounds you: pine needles. Portions of the trail are thickly padded with them. They dangle from branches of all kinds, caught as they fell from the cypress canopy above.

The creation of iron ore begins with these pine needles. As rain water soaks through pine needles on the forest floor, it becomes acidic. The acidic water then dissolves and absorbs iron from the sandy soil, and moves it through the water table. Eventually, the water resurfaces. When it makes contact with air, the iron oxidizes out of the water and forms iron ore. Especially rich deposits, known as bog iron, form in the slowly moving waters of swamps.

“In 1788, prospectors came looking for bog iron here, and they found it,” Fisher said. “They formed the Maryland Iron Company with investors from Maine, New Jersey, Maryland, Pennsylvania and Virginia. But nothing happened until 1828, when Maryland offered a tax break for companies producing iron. That’s when they bought the land and went into business.”

The first job at hand was to construct the furnace.

The Nassawango furnace, like others of that period, is a tall, narrow structure that is wider at its base than at its top.

During early efforts to preserve the site, archaeologists made a surprising discovery. “The furnace was built on a 24-foot cypress raft to prevent it from sinking as they built it,” Fisher said.

The furnace eventually found solid footing and stands firm after more than 150 years. Other transformations to the landscape, although larger in scale, have fortunately not proven as permanent.

“They left the place a barren sand hill,” Fisher said.

A short distance from the furnace, workers cleared land to create a 300-acre holding pond. Water from the pond flowed along a millrace to a waterwheel at the base of the furnace. The wheel powered giant bellows that fanned the furnace flames with great blasts of air. The path of the millrace is still clearly marked by a depression in the land, but the pond has long since returned to trees.

Where water exited the water wheel, workers constructed a canal. Today, the Paul Leifer Nature Trail merges with the old tow path, so that visitors can walk along the canal bed—in-filled and shallow, but still wet.

“It’s a spring-fed canal,” Fisher explained. “It always has water, but never freezes. The temperature is basically 55 degrees, all year round.”

At several spots along the canal bed, visitors can see patches of soggy orange sediment forming at the water’s edge. These are called “iron seeps.” Here, the canal springs carry iron-rich water to the surface, where it oxidizes and eventually transforms into bog iron.

While it operated, the canal provided a critical transportation route to Nassawango Creek, the Pocomoke River and ultimately, the Chesapeake Bay. Canal boats ferried pig iron to waiting ships, and returned laden with oyster shells to feed the furnace.

Oyster shells were needed to separate iron from other components in iron ore. Simply melting the ore wouldn’t do the job. By combining the ore with oyster shells, and subjecting them to extreme heat, both decompose and recombine. In the process, calcium from the oyster shells draws out impurities from the iron ore and binds them together. The result is called slag.

Slag is lighter than iron, and rises to the top of the molten mass inside the furnace. Workers at Nassawango used spouts to draw off the slag—which cooled into glassy bluish lumps—then dumped it into the swamp.

Liquid iron was gathered from spouts low on the furnace base, where it was channeled toward molds for cooling. Each mold featured a large oblong bar, with smaller bars positioned perpendicularly at both sides. Together, they resembled a sow with piglets at her side. The results were known as pig iron.

Work at Nassawango Furnace was intense, dirty and dangerous. Men worked long, uncomfortable hours in the swamp to extract the ore, smeared with bear grease to combat mosquitoes. Lumbermen harvested timber and colliers conducted long, slow burns to convert lumber to charcoal. Teamsters moved the materials about, while furnace men and foundry workers handled the iron directly.

A 25-acre town sprung up to support the Nassawango furnace and the families who lived here. At its peak, the town played host to approximately 300 people.

“There was a bank, a general store, a post office. It was a fully functioning town,” Fisher said. “But it was a company town. Everyone was paid in script.”

The tidy buildings on the site today depict 19th century family life and the workshops of printers, broom makers, weavers, blacksmiths and carpenters. They are period buildings from Worcester County, including a serene, one-room chapel, although none are original Furnace Town structures.

Furnace Town closed in 1850, as the market moved west for better quality iron. Ironically, railroads built with Nassawango iron helped to propel these distant markets and put Furnace Town into bankruptcy.

“From 1850 to 1880, only 15 to 20 people were still here,” Fisher explained. “They operated a grist mill and boarding house because this was a main stage route. But little was left standing by the turn of the century. Everything was made of wood—cheap and dirty.”

To make matters worse, a fire devastated the peninsula in 1930 and left little standing in its wake.

The furnace, though, remained rooted on the land and in the minds of local residents.

“Since the 1890s, young men brought their girls out here in their surreys. ‘Sparking,’ they called it then,” said Fisher. “It became a local landmark, a Sunday drive thing to do. Kids would climb all over it.”

Preservation interests stirred during the 1930s, when an effort was made to stabilize the furnace base. About 30 years later, Worcester County Historical Society mounted a more sustained attempt.

“Some of the same men who’d gone climbing and ‘sparking’ in their days got together and hauled out truckloads of cans and bottles and debris. But remarkably, the furnace hadn’t been damaged,” Fisher said.

The historical society partnered with the county and the last of the land’s private owners to secure the site for preservation and interpretation.

Although a number of 19th century foundations have been identified, Fisher said their goal is to give “an idea of a village,” rather than recreate the village that actually stood here. About a dozen historic buildings were moved to the site, beginning in 1977. The Nature Conservancy began preserving the adjacent swampland in 1978.

Today, visitors at the Furnace Town Living Heritage Museum and The Nature Conservancy Nassawango Preserve will find it bustling with children and craftsmen. But they will also find quiet moments among quaint kitchen gardens, organ music piped softly into a sunlit chapel, and a wet, wooded sanctuary where the natural environment flourishes once again.

Furnace Town Living History Museum & The Nature Conservancy Nassawango Preserve

Furnace Town buildings and interpretive programs are open 10 a.m. to 5 p.m., April 1 to Oct. 31.

The grounds and nature trail are open in the off-season.

Admission to Furnace Town and the Nassawango Preserve is free for members of The Nature Conservancy or the Furnace Town Foundation with a valid membership card. Admission for nonmembers is $4 for adults; $3.50 for adults older than 60; and $2 for children ages 2–18. Visits to the grounds and nature trail in the off-season are free of charge.

Getting there: From Salisbury, take Route 12 south for 14 miles. Turn right on Old Furnace Road. Furnace Town is one mile ahead on your left.

From Ocean City, take Route 50 or Route 90 west to Route 113 south. Follow Route 113 to Snow Hill, following Business Route 113 into Snow Hill. Turn right at the traffic signal onto Route 12 north, and continue for four miles. Turn left onto Old Furnace Road. Furnace Town is one mile ahead on your left.

From Virginia, take Route 13 north to Pocomoke, then Route 113 north toward Snow Hill/Ocean City. Turn left onto Business Route 113 through Snow Hill. Turn right at the traffic light onto Route 12 north and continue for four miles. Turn left onto Old Furnace Road. Furnace Town is one mile ahead on your left.

For information, contact the Nassawango Furnace Town & Nature Preserve at 410-632-2032 or P.O. Box 207, Snow Hill, MD 21863 or visit