BUCKS HARBOR, Maine -- It might seem tempting to think of William Coperthwaite, who has adopted a life and lifestyle in the Maine woods substantially separate from civilization, as a modern-day David Thoreau.
His Walden Pond is Mill Pond and his Concord is Bucks Harbor, a Down East village in Washington County. He lives in a three-story yurt reachable only by the sea or by a half-hour's hike along a woodland footpath bordered by bunchberry and sphagnum moss. Coperthwaite is highly learned -- he earned a doctorate in education from Harvard in 1972 -- and idealistic.
But unlike Thoreau, described by Ralph Waldo Emerson as a somewhat cranky, antisocial ascetic, Coperthwaite is a friendly, open-minded fellow who warmly welcomes visitors to his round house and invites them to finish the organic cantaloupe left over from breakfast. In mind and body, he is boyish, with a lean build, vigor, and curiosity that belie his 75 years.
A runner and pole vaulter as a Bowdoin College undergrad, he gets a daily workout chopping firewood, hauling supplies in his cedar canoe, pulling fir saplings from maple and birch glades, and performing other regular chores. To meet other needs, he splits firewood, collects rainwater, and walks or canoes in and out with the tides by way of Little Kennebec Bay.
Blue eyes twinkling beneath bushy eyebrows, and gray sideburns sticking straight out from his balding head, Coperthwaite exhibits a keen interest and sense of wonder in new technology. He marvels over a newspaper photographer's Canon and digs out the Casio Exilim card camera someone gave him recently to document utilitarian folk art at risk of being lost.
When he bought his 300 acres in this remote hamlet, whose year-round inhabitants number 250, in 1960, it was to embark on an experiment in sustainable living that is still underway. Doing much of the work himself, with friends pitching in from time to time, he built a smaller yurt down by the spruce-lined shore, and completed the main yurt and outbuildings later, in between teaching posts and travels abroad. Today, the outward-curving walls, hand-cut cedar shake roofs, and banks of windows under the eaves of the weathered dwelling blend with the landscape. A blue glass ball atop the cupola sparkles in the sunlight.
He lives in his rustic abode, which rises like a pagoda in a meadow, largely alone, save for the steady stream of visitors and friends; he was married briefly years ago, but the relationship didn't work out. He is untethered in other ways as well. Although a solar panel attached to the chimney provides light, the yurt is off the electric grid, and he has neither plumbing nor a telephone.
Coperthwaite not only lives in a yurt, a housing form conceived by nomadic Mongols on the steppes of Central Asia 2,500 years ago, but he has made it a cornerstone of his working life. He once built and lived in a yurt where the Harvard Graduate School of Education library stands today. He is founder and director of the Yurt Foundation, a nonprofit research institute he operates from his outpost. He has spent much of his time teaching others to construct the circular dwellings, and his pupils have built structures ranging from a public health center in northeastern India to a backyard playhouse at a Montessori school in Austin, Texas. Construction materials have varied widely from bamboo to plywood, depending on climate and setting. He also supplies building plans to those who want to construct the curvilinear structures on their own.
Despite his absorption with the ancient dwellings -- which when built right withstand violent winds and extremes in outdoor temperature, staying warm above minus-40 degrees and cool below 100 degrees -- Coperthwaite would tell you they are only part of his broader work researching folkways and subsistence skills that can be adapted to contemporary living. His thoughts and research are presented in ''A Handmade Life: In Search of Simplicity" (Chelsea Green, 2003).
''The main thrust of my work is not simple living, not yurt design, not social change, although each of these is important and receives large blocks of my time," he reflects in his book. ''But they are not central. My central concern is encouraging people to seek, to experiment, to plan, to create, and to dream. If enough people do this we will find a better way."
Born in the northern Maine town of Monticello, Coperthwaite majored in art history at Bowdoin. He was a conscientious objector during the Korean War and later taught at the North Country School in Lake Placid, N.Y., and the Meeting School in Rindge, N.H. At the latter, he and his math students came across a National Geographic article about Mongolia and pictures of portable yurts invented by nomadic Mongols. They were impressed by the indigenous design consisting of a collapsible circular trellis (picture an old accordion-style baby gate) that could be carried on camels and assembled in an hour. The wooden framework was set in a circle and the doorway lashed into place. Willow saplings were attached from the walls to a wooden ring at the apex, where a hole let light in and wood smoke out. A tension band was then tightened around the entire structure at the eaves.
The yurt was covered in multiple layers of thick felt made from beaten wet sheep wool. The shelters are still being used in much the same way today in a 5,000-mile expanse from Turkey to China.
The native genius, Coperthwaite says, lies in the use of the tension band to take the outward thrust of the conical roof. The thick rope, made of yak or horse hair, eliminated the need for internal posts, rafters, lintels, headers, and joists.
''They could increase the space in their circular tents by raising them on a low wall, providing support by tying a rope around them," he notes in ''A Handmade Life." ''The structure, made of light poles fastened with felt and bound together with bands of woven wool, was a brilliant solution to the needs of that harsh region's people."
Coperthwaite and his students modified the yurt by making its walls flare at the top, creating greater spaciousness within. Over the years, he has adapted the ancient design for permanent habitation. He replaced the collapsible framework with solid tapered boards. The tension produced by the conical roof and outward sloping walls is contained by a steel band encircling the structure. Windows added under the eaves augment the natural lighting supplied by the central skylight. Coperthwaite aimed -- and still strives -- to design attractive, inexpensive dwellings that amateur builders can construct for themselves in a reasonable time frame and maintain at minimal cost.
''My goal was to design this structure so that it could be built in stages to allow a family to start out with a very limited outlay of money, time, and energy, then expand the building as their resources grew," he writes. ''I aimed at an initial budget of $3,000. This figure would permit many people to bypass a mortgage, avoiding the usurious rates of the money lenders as well as their veto power over the design and time frame."
Inspired by Gandhi, American pacifist Richard Gregg, North Country School cofounder Walter Clark, back-to-the-land movement leaders Scott and Helen Nearing, and others in the 1960s, Coperthwaite says the yurt became a metaphor for his larger mission to create a more truly democratic society that would value folk wisdom and practices.
As he conducts a tour, Coperthwaite shows his spacious workshop where sawdust and wood shavings carpet the wooden floor. Much of his time is spent here making chairs, tables, bowls, knives, and other household items. All the pieces fill utilitarian functions but are beautiful to behold, whether they are crooked knife handles carved from a beech burl or brooms fashioned from birch shavings.
''If living is to be right, it ought to be beautiful," declares Coperthwaite, whose cupcake-shaped outhouse is a thing of beauty. ''So often it goes by the board."
The second floor feels like being on the bridge of a ship at sea. It takes a moment to adjust visually to the windows and curving walls, whose tendency to catch dust, unlike vertical walls, is Coperthwaite's only complaint of the form. A settee, its cushion fashioned from rolled-up strips of discarded sweaters, and leather sling chairs provide comfortable seating in the main living space. Gold raw silk covers one wall and adds warmth to the room on dull winter days.
''The Dickinsons Reach easy chair," Coperthwaite quips, referring to the sling chairs. ''Easy to build, easy on your pocket, and easy on your back.
Anyone can build them. If they're not comfortable, they're not worth building."
A sleeping loft occupies the third story. The airy space is sparsely furnished with a bed, a basket for hand-knit socks, and separate wooden bins for pants, shirts, windbreakers, and other garments. An even loftier perch -- a cat's cradle of monofilament fishing line -- has been cleverly created just below the skylight.
Outdoors, Coperthwaite points out his summer kitchen and other smaller yurts scattered around the property before leading the way down to the shore, where an old birch bark canoe and other craft are stored in a boathouse. He shows his outdoor shower -- a saltwater pool that fills and empties twice a day, hidden from view and shielded from the wind by a wall of flat fieldstones collected over the years.
''The more you have participated in making things around you, the more pleasurable it is," he muses. ''I think we have gotten away from that in our society."
This spring, Coperthwaite intends to visit Bolivia's Altiplano -- a high, rugged plateau inhabited by the Aymara and Quechua people -- to do research. But he has no desire to escape from his roundabout way of life.
''I am lucky in that I enjoy how I live and what I am doing," he says.
William Coperthwaite sells building plans for three basic yurts, ranging from 10 to 38 feet in diameter, for $25, $50, and $75. Revenue supports his research of folkways and traditions. He also welcomes correspondence. Write to: The Yurt Foundation, Dickinsons Reach, Machiasport, ME 04655.