This is the fourth in a six-part, yearlong series called Disappearing Virginia in Distinction magazine. This story originally appeared in the August issue as “The Treasure of the Tide.”

The boxy old building hides its importance well. Its weathered clapboard siding is faded and curling with age. The structure is visible to the public only by water, and even then it’s not all that conspicuous, looking more like a timeworn barn than a landmark. Yet this plain frame is a singular relic in the mid-Atlantic – the last standing mill that captured the potent energy of the tides.

Poplar Grove is a pastoral estate overlooking the East River in Mathews County, its broad plain bending toward the Chesapeake Bay from Virginia’s Middle Peninsula. The property’s centerpiece is a grand manor that first made its debut around 1750 and had four sections added though the years. Ancient trees frame the view across a sweeping lawn that spills down to the waterfront.

But the tide mill, settled in a far corner of the property, at the seam of water and land, is no less a treasure. First built in the latter half of the 18th century, the mill through the years has been touched by war, destroyed and reborn. That the property once belonged to a handful of noteworthy owners including, of all people, one of The Beatles, richens its story.

Most remarkable is that this mill remains at all, serving as a tangible link both to a past that has faded from living memory and a future that may bring our need for renewable energy full circle.

Poplar Grove’s Tide Mill. Photograph by Keith Lanpher.

Mills, to some, are little more than quaint throwbacks to a simpler era. To our pre-modern ancestors, though, they turned grain into sustenance, wild timberland into lumber, stalks into fiber. Mills drove progress and helped make our civilization what it is today.

Before the ubiquity of electricity, people cornered free energy that made mills move – in the wind that blew over open spaces, in the water that flowed downhill from high ground. But for residents of coastal stretches, there was another source: the daily ebb and flow at their feet.

A tide mill captured the energy that washes over local shores about every six and a quarter hours. The idea was simple: Build a berm across the mouth of a tidal creek that loses and gains a couple vertical feet with each tide. Insert floodgates, which can let the water in, be closed when the creek is full, then opened once more at low tide so that the concentrated, outgoing stream flows across a water wheel, transforming that current into energy. A tide mill was reversible; the high tide could be shut out of the creek by the floodgates and then let in all at once to capture energy coming in, too.

Such mills were effective, reliable and strong – energy provided by the endless rhythm of the lunar cycle. In New York and points north, where the vertical change of the tides is pronounced, there were perhaps hundreds of tide mills. There’s no reliable count for the Chesapeake Bay’s tributaries, but there were certainly scores, and not only in obvious places, as with Tide Mill Lane in Hampton.

In the 18th century, John Hollowell, who lived about 9 miles from Norfolk on the Western Branch of the Elizabeth River, owned a tide mill that could reportedly “grind from 6 to 8000 bushels of grain in a year,” according to a July 1766 advertisement in The Virginia Gazette.

So Poplar Grove had many contemporaries. Slaves likely built the dam across the finger creek that now makes the southern boundary of the estate. A mill existed there in the late 18th century; legend holds that the miller ground grain for patriots under George Washington’s command. That original mill burned during the Civil War. The owner replaced it soon afterward, and the millstone turned until about 1912, when changes in technology and agriculture made it obsolete.

Poplar Grove’s reconstructed water wheel. Photography by Keith Lanpher.

Through the years some notable people have owned Poplar Grove. Sally Tompkins, who was commissioned a captain in the Confederate army – an appointment afforded only a few women – was born there. At the outbreak of war, she and her family fled to Richmond, where she treated sick and wounded soldiers and earned the name “Angel of the Confederacy.” Tompkins is one of 12 Virginians being honored with a bronze statue at the Virginia Women’s Monument under construction on the grounds of the state Capitol.

Author Joe Upton spent time at Poplar Grove when his grandfather, George Upton, owned the estate. The author spent 30 years as a commercial fisherman, and recounted some of his adventures in the book Alaska Blues: A Story of Freedom, Risk and Living Your Dream.

In 1980, John Lennon and Yoko Ono bought Poplar Grove as a country home. But Lennon’s ownership was brief; he was shot to death nine months later in New York City, and a few years afterward, Ono donated Poplar Grove to a boys home.

Bernadine Teague, an affable and energetic 87-year-old businesswoman, has owned it since the 1980s. She has worked since then to maintain the estate, including the main house, grounds and gristmill. “I definitely have my hands full,” she says, ticking off a list of upcoming priorities for the property, including a new wooden shingle roof on the mill. “It’s constant work.”

For an exposed building a century-and-a-half old, however, the tide mill is in fair shape. The interior contains all the shafts and gears that once turned the millstone, which also remains. Ideally, Teague would like to see the mill in working condition again, although it won’t operate as before: The berm that separated the lagoon from open water breached long ago. Nevertheless, the mill is dear to people. “Everybody loves the mill,” she says. “People want to have their wedding pictures and high school pictures there. Some of them come on horses.”

The Poplar Grove estate, and especially the mill, is a beloved part of the Mathews community, says Wesley Sanger, a lifelong county resident and carpenter. The connection to major figures and past episodes puts Mathews – fiercely protected by residents for its tranquility – in a larger historical context. In 2015, Sanger made a new mill wheel to replace the one that Hurricane Isabel destroyed.

C.W. Hudgins Jr. is a Mathews businessman who has lived near Poplar Grove all of his 72 years. He lived in the main house from 1957 to 1963 while his father was the estate’s caretaker, an arrangement he says was “a poor man living in a rich man’s house.”

He has fond memories of Poplar Grove. The Hudgins family would host parties for graduating high school classes on the estate. He remembers, too, that sheep and cattle grazed on the lawn next to the mill and mansion. One night the family awoke to a clamor, only to discover a bull on the wide, wooden front porch.

As the property’s unofficial historian, Hudgins keeps a thick file of pictures, drawings and accounts that offer candid glimpses of Poplar Grove’s history, such as the existence of a miller’s house that once stood next to the mill.

Inside Poplar Grove’s Tide Mill. Photographs by Keith Lanpher.

Part of its charm, too, is that the mill is among the last of its kind. Located at the junction of land and sea, such mills have always been vulnerable to tide and tempest. One by one, victims of age and neglect, they fell in on themselves. Fewer than a dozen tide mills remain on the East Coast; all the others are in the Northeast. Poplar Grove’s may be the only tide mill with its internal hardware still intact.

This unvarnished, exceptional structure stands as a testament to energy that moved old-time Americans forward. And it may be a symbol of what’s to come, too. Although wind and solar now receive the bulk of attention as sources of renewable energy, scientists are actively testing viable means of capturing power from ocean currents, waves and tides.

Marine energy may be an innovative idea in our quest for progress, but it’s one that a humble, out-of-the-way mill on a remote shore – and countless others like it – used long before we recognized a need to return once more to inexhaustible forces of nature.