Cover image for Smithsonian Magazine referred to below. Credit Ken Canning / Getty Images.

I think nearly every Connecticut resident would agree that the stone feature shown above meets the definition of a stone wall. Smithsonian Magazine certainly thought so, when it chose this to be the cover photo of an extended essay I published on November 14, 2023.  And it certainly meets the scientific definition I published in the peer-reviewed mini-monograph for the scholarly journal Historic Archaeology.  My definition requires that a stone object be a linear, continuous, granular feature made of stones that either rest one above another or reach knee high.

Alas, the feature above, and millions of others like it, may not meet the official Connecticut state definition of a stone wall, which I only recently stumbled across.  This definition is part of new law to prohibit the destruction and theft of stone wall, a laudable goal that I support.  Specifically, I refer to Section 3 of Substitute House Bill No. 5400 (File No.708) of the House of Representatives passed unanimously on March 10,2023 by Environment Committee (33 Yea, 0 Nay), and passed unanimously by the Judiciary Committee  (36 Yea, 0 Nay) on November 19, 2023.  I quote lines 8-11 of Section 3 in full below:

(3) For purposes of this section, “stone wall” means a vertical structure of aligned natural stone customarily arranged with a stone coursing pattern that is marked by the utilization of consistent stone type, joint width, construction and the distribution of stones by size.

The language of the summary of the bill sHB5400 is slightly different.  “The bill defines a “stone wall” as a vertical structure of aligned natural stone typically arranged with a stone coursing pattern that uses consistent stone type, joint width, construction, and distribution of stones by size.”  From this, it’s clear that official language of section 3 is a definition (“The bill defines…”) , and that the summary phrase “customarily arranged” from Section 3 is equivalent to the phrase “typically arranged” in the summary.

Where to begin?  I’ll start by saying that if I were on one of those committees, I would have voted no, listing my reasons below.  Imagining myself as a lawyer or a technical copy-editor, I’m going to be very persnickety, quibbling with each term as they occur in sequence.

MAIN DEFINITION

“Stone Wall” – The object being defined, a “stone wall,” is placed in quotes.  Why? Perhaps this is legal custom.  But what if it means that the term “stone wall” as used indeterminately, the notion that  one person’s wall another’s non-wall? As with the term “xerox” for every copy machine.

“Vertical “-   What does this mean?  Let X be the line of the wall, Y be across the wall, and Z be the height of the wall.  On  a sloping hillside, the case for most of Connecticut, a perfectly built wall can be vertical in cross section (YZ), meaning it’s perpendicular to grade. But it is not vertical in the line of the wall (XZ) when viewed from either side. In this case the wall is perpendicular (normal) to the slope, rather than the vertical vector of gravity.  Does the law require that a wall be vertical in both directions? Or just one?  Which one?  Additionally, I’ve seen many free-standing (has two sides, or faces), if not a majority, of walls that are tipped or angled downslope.  Walls can lean up to ~20 degrees before they collapse. Finally, retaining walls are abundant, and none are vertical.  Rather, they are built with a facing slope of about 8 degrees. These are not walls by the state definition.

“Aligned” –  I think this is the wrong word because it lacks a frame of reference.  Aligned with what? The stars? A fenceline?  Itself?    A better term is “elongated.”   Stone walls are definitely elongated.  But so are ellipsoidal piles, regardless of their alignment direction.   And what about curved walls?  By definition, they are not aligned.  Only their tangents are aligned.   I’ve seen plenty of broadly curved walls and many stone cisterns measuring meters across that are circular, rather than aligned.

“Natural”–  Though this word is deeply embedded in our language, its highly contentious. There’s plenty of  nature in human nature, for example our bodies.  A human damming a stream and a beaver damming a stream are fundamentally the same action.  I have long argued that the typical crude stone wall is an expression of pre-petroleum human ecology.  There are plenty of conglomerates out there that resemble concrete, and plenty of stones that resemble brick.  To suggest that a stone wall built of created stone is not a stone wall begs the question of how accurate a replica must be.

By Connecticut state law, this is unusual stone wall in Tyringham, Massachusetts probably not a stone wall because it is not “customarily” or “typically”  arranged.” Credit: Bess Dilman. 

DEFINING CLAUSE

At this point, there are two ways of looking at the grammar of the definition. After the word “stone” comes a single long clause beginning  with “typically” and ending with “size.”  The first part of the definition “a vertical structure of aligned natural stone” could be taken as the whole definition. But if so, steep cobble beach ridge and a weathered volcanic dike would meet this restricted definition.   Thus, I  think the second clause is also essential,  meaning  that it word-paints the object being defined so that we would never mistake a farmstead wall for other geological features.  The main idea is that, if it doesn’t look “typical,” it isn’t a wall.

“Customarily arranged” – By whose custom?  This is undefined.  The bill summary indicates that “customarily” is a synonym for “typical,” but these words mean something quite different. The former refers to a cultural practice. The latter is a statistical.  In either case, if a wall is atypical, such as the one above, or if doesn’t follow the some local convention, it’s not a wall. This is absurd.

This wall in Monterey, MA is not “customarily arranged,” does not have a “stone coursing pattern,” there is no “consistent stone type, joint width, construction and the distribution of stones by size,”  all features within the definition. Credit Sam Wadswworth.

“Stone coursing pattern” – Most of New England walls are either not coursed, as with the photo above, or the coursing is only weakly and locally expressed.

“Consistent stone type” – This is not defined. Type usually refers to material composition (lithology), as with granite vs. limestone. Since “size” is later specified in the definition, perhaps “type” refers to shape, as with slab vs. boulder.

“Distribution of stones by size” –  This works locally because in most settings, there is a common range of sizes.” It can’t work extra-locally because the geology changes and that’s the main determinant for particle size distribution.

I’m hoping that this blog post, eventually  finds its way inside the halls of the Connecticut State House, or those of other state houses, so that we may eventually improve the legal definition of a stone wall.  I’m glad to help.  Please feel free to contact me in this regard.

 

 

 

 

 

Photo of a historic stone wall, probably in Glastonbury, Connecticut.  For inventory purposes, this would be a single segment of an uncapped, single-tiered, un-coursed, double wall with a re-built termination.  Aside from being an aesthetic and archaeological resource, this wall is also a dryland habitat and an ecological barrier, corridor, and partitioner.  Courtesy of Paul Ramsey.

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In Spring 2025, The Stone Wall Initiative is ramping up its activities with a series of events, projects, and talks based the recent article Conserving the Historic Stone Walls of New England, which was published  in the peer-reviewed scholarly journal The Public Historian in February 2024. As of this posting on April 4, 2025,  historical societies, conservation organizations, land trusts, environmental non-profits, garden clubs, and town planners in Ashford, Mansfield, Litchfield, Stonington, Lyme, and Sherman, Connecticut, in Cumberland and Little Compton, Rhode Island, and at Quabbin Reservoir in Massachusetts are working with me to help implement A Stepwise Coordinated Plan for Stone Wall Conservation. This last link will take you to  an article of title by staff writer Elaina Hancock in the University of Connecticut’s online magazine UConn Today.  In it, she provides a concise review of the Public Historian article as a good first-read for anyone wanting to jump start the process.

It’s one thing to talk about stone wall conservation in general, which this website has been doing for decades, and which I have most prominently featured in the New York Times and the Smithsonian.  It’s quite another to get down to the nitty gritty of managing them on private, trust, town, state, federal, and Indigenous lands.  This takes the commitment, time, and a budget of organizations

Four recent events have made conservation of walls more efficient, more objective, and more important.

1. Within a designated GIS layer for the Stone Domain, a top-down map of stone features based on LiDAR technology can be combined with bottom up inventories from known historic sites.
2. The recently published Taxonomy and Nomenclature of the Stone Domain provides a peer-reviewed and vetted classification for an inventory of stone features.
3. Increased attention to Indigenous stone features requires that the broader context of Euro-settlement features be known from inventory, and
4. Increased attention to walls as dryland habitats equivalent in principle to their counterparts of wetland habitats.

Once in place, a GIS layer for the Stone Domain provides solid ground for management, ultimately for the benefit of conserving these irreplaceable historic and ecologic resources for future generations.

If you would like to discuss how to proceed,  just contact the SWI via robert.thorson@uconn.edu.

 

Unusual stone wall in Tyringham, MA.  Credit: Bess Dilman. 

Last Year, a devoted hiker named Bess Dilman kindly sent me some photos of an unusual New England wall located near the Appalachian Trail in Tyringham, MA.  It’s been puzzling her for a while, and others were equally bemused.  So, she wrote to see if I had an opinion.  Of course I do!

My opinion –coming from stone wall science– is that we should always describe what something is before we begin speculating about why something exists.  The intermediate step in this process of reasoning is called classification, the creation and naming of categories.

I decided to use her request to feature why New England needs a standardized nomenclature for describing its stone walls, and a classification large enough and flexible enough to cover ALL kinds.  Last year, after 20 years of collaboratives work, I published just such a nomenclature and classification in the peer-reviewed journal Historical Archaeology.  This mini-monograph, titled “Taxonomy and Nomenclature for the Stone Domain in New England,” is a tool that I hope will help.  The  Stone Wall Initiative  website may also be helpful.

STONES:  The shapes range from blades to tablets, the former being longer relative to their widths. These shapes are usually quite rare within what I call the glacial mix because such thin sheets of rock are easily crushed, and their corners and edges rounded off.  The composition or lithology is amazingly uniform.  Every stone in sight seems to be the same composition, some sort of granitic gneiss with broad foliation folds intact, suggesting that all the stones were described from the same local source, perhaps an ad hoc quarry, an outcrop, or a large split slab.  Were glacial fieldstones involved, other lithologies and shapes would be present.  The presence or absence of marks (drill-holes, flaked shape, intentional breaks would provide a clue here.  The size of the stone is as unusually uniform as its shape and lithology.  With one possible exception, all are what I call “hefted” stones, those small enough to be lifted and set into place by human muscle.  In an earlier version of my nomenclature, I called them “two-handers.”  The degree of order of the stones is clearly what I call “patterned,” the highest degree of order, meaning there was some sort of artistic or architectural intent above and beyond being  “laid” (fitted and planned like outdoor chess), which is above and beyond “stacked” (crudely stacked above one another), which is above and beyond being “dumped” (randomly pitched or tossed with no stacking or fitting).

SUBSTRATE:  The broad curve of the landscape grade at the base of the wall, and the sharp tips of all stones at the bottom, suggest that the wall rests on a glacially smoothed boss of rock. Otherwise the stones would have been pressed downward into forest duff and topsoil. The apparent precariousness of the stones supports this interpretation because any significant settling would have likely caused collapse.

DEFINITION:  Within the domain of all historic stone objects, this is a wall because it meets all five criteria.  Composition: made of stone.  Granularity: made of particles or grains or stones, rather than a single large slab of rock.  Continuity:  continuous along its length.  Elongation: more than four times (arbitrary threshold) longer than it is wide.  Height: is both knee-high (arbitrary threshold) and has stones resting on stones.  This puts it in the class “wall” rather than the classes concentration, line, or notable stone.

STRUCTURE:  I see no foundation tier. So it’s a two tiered wall with a basal group of more massive stones laid diagonally downward toward the left, and a higher tier laid either downward to the right (to create a chevron pattern) or horizontally.

DIMENSIONS:  I’m guessing it’s a thigh-high, and one-stone wide rectangle in cross section (the YZ plane). If wider at the base, it’s trapezoidal in cross section

TAXONOMY:  We’ve already established that, within the stone domain,  this is in the class wall.  Within this class, it’s in the family freestanding wall, because it has two sides.  Within this family, it’s a type known as a single wall because it was not built of two sides slanted in toward each other for stability.  Within this type, it is a panel subtype because it is an upward stack of stone where wall width and stone width are the same.  Within this subtype, it’s an open variant because there is no attempt to minimize the pore spaces by fitting stones together.

INTERPRETATION: Colloquially, this is known as a lace wall, though it’s a very unusual one because this shape stacks so easily to minimize pore space. Most lace walls are made of rounded ball-shaped stones which require high porosity and stones not bearing weight are very unstable.  Now, having described it with a nomenclature and classified with with a taxonomy, we can  speculate on why.  This wall makes no sense as a “linear landfill” for field clearing. It might have been a fence, but seem too low.  It could have been a border to a field or farm.  So, let’s call it an unexplained anomaly, perhaps an idiosyncratic, “what the hell,” folk art expression of some sort, likely built from locally quarried stone on bedrock.  A reconnaissance of the terrain would  provide other clues. But for now, let’s just call it a “Bladed Lace Wall.”

If you have an odd wall you want interpreted, please feel free to send me some descriptions and images.  Perhaps I’ll start a separate section of the website for this.

 

 

“Ecologically, stone walls are elevated, dry, rocky, and porous volumes, surface areas, and lines within an otherwise moist woodland, providing novel habitats, exposures, boundaries, and corridors. By retaining moist sediment, the uphill side of this wall supports luxuriant ferns in the background. The drier downhill side supports grass and herbs in the foreground. Holyoke State Forest, Massachusetts.” 

Historically, the inland wetlands of New England were critical to indigenous lifeways.  To the European settlers, however, they were generally seen as nuisances on the landscape: obstacles to transportation, sources of disease, and wild lands waiting to be redeemed by drainage and clearing. During the 1990s, the more hidden values of inland wetlands became widely known, with a specific focus on wildlife habitat, flood mitigation, water quality, and education.  Regulations soon followed, and protected wetlands are now broadly appreciated and enjoyed by the general public.

During the mid 1990s, I was heavily engaged in the investigation and management of New England’s inland wetlands as a research scientist.  Simultaneously, I was working on New England’s signature landform, the iconic fieldstone walls that emerged from the region’s colonial and early American stages before widespread access to fossil fuels.  The end result was up to 250,000 miles of stone walls cross-crossing rural New England. More than half of these remain, mostly in woodlands that were once field and pasture.   During the last few years, I’ve paid increasingly attention to the ecological role of walls as habitats and their hydrological roles within watersheds.

During one of my recent talks –increasingly online– I began researching the parallel between wetlands and drylands.  The EPA’s popular pamphlet Functions and Values of Wetlands opens with these words:  “Long regarded as wastelands, wetlands are now recognized as important features in the landscape that provide numerous beneficial services for people and for fish and wildlife.”  Quite suddenly, I realized that if you swapped in the word “dryland” for the word “wetland,” the sentence would still work nicely, with one exception.  A dryland wall submerged by flooding would no longer be dry, but would still diversify habitat as an underwater reef.  My most recent thinking on this phenomena will be published in the February 2025 (Volume 47) issue of the scholarly journal The Public Historian, which quote in the caption above and the indented text below 

Like natural talus slopes or mountain scree, stone walls are dry, granular, linear, rocky landscape elements in an otherwise moister, soil-covered, vegetated landscape. The lichens, moss, and microbial mats on walls exist nowhere else except for bedrock exposures and large boulders. The higher thermal heat capacity and conductivity of stone cause walls to retain the cold of night and the warmth of day longer than the adjacent soils, creating novel ecological opportunities. During winter and summer, they conduct heat more efficiently into and out of the ground, creating seasonal bulbs of frozen ground and thawed soil. As porous volumes, walls and concentrations provide homes for creatures needing protected places. Insects, rodents, and snakes are common, and the dens of larger burrowing animals are frequently beneath basal stones. As geographic areas, walls are small, but as an aerial gridwork, they broadly pixelate the land surface. As lines, walls are borders between adjacent habitats, and corridors connecting distant habitats. 

The ecological effects of walls extend well beyond the dryland edges. As stable ridges, their opposite sides are sunny vs. shaded, windward vs. leeward, and upslope vs downslope. This changes the local seasonal phenology of dry vs. wet sides, snow-covered vs. snow-free, accumulation of soil vs. erosion of soil. All of these differences greatly increase the details of habitat texture, enhancing biodiversity. A loss of walls is a loss of biodiversity.

Walls are the dryland counterpart of inland wetlands. These impermeable, exposed, ventilated habitats contrast with the saturated soils of nearby wetlands on the same land parcels.  Prior to the early 1990s, and except for early ecologists and conservationists, inland wetlands were usually considered blights on the landscape. Cultural incentives and land regulations fostered destruction via drainage and filling. Only after the hidden values of wetlands were clearly connected to the lives of ordinary citizens were they protected. This same narrative applies to stone wall drylands. Prior to having their hidden values recognized, many of New England’s walls were strip-mined and crushed for road gravel, buried to enhance drainage, or quarried for fill or building stone.

Counterintuitively, stone walls and inland wetlands were often created by the same agricultural transformation. Sediment eroded from hillsides concentrated the upland stone that became walls. When deposited at lower elevation, that same sediment occluded drainages and aggraded floodplains to create and enhance many wetlands.

My fervent hope is that increased scientific and public recognition of the habitat diversification provided by New England’s signature landform will strengthen the movement to conserve as many as possible.

Screenshot of 44-second video by Sam Wadsworth from late December, 2023. It shows oversized stones pushed and set on a wall in Monterey, Massachusetts. This large, glacially milled boulder rests above a classic mix of sharp-edged (slabs) and round-edged slabs (pillows). The diagonal line from upper left to lower right is a recent and sharply broken edge, with the upper side having a rounded (milled) surface with a moss-lichen-patina and the lower side having  jagged fresh rock on which may be vertical scrape marks running against the grain (metamorphic foliation).  Because the boulder rests on stones that are continuous across the gap in the wall, I interpret that the boulder was moved, broken, and scraped in the recent past by a large machine fueled by petroleum.

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During the dark days of  December a curious character from Monterey, Massachusetts named Sam Wadsworth contacted me from the heart of the Berkshires.  Having read my book Stone by Stone, he reached out to ask me two two excellent questions that I decided to answer in this post as a surprise, rather than an email.   He asks: What is “the maximum size/weight of boulder that could be moved by man and oxen”? He also asks:  Did the farmers who cleared the land “arrange stone walls to include such giant stones or did they move them”?

Though both questions are straightforward, neither has a good answer that I know of.

The second question is easier, so I’ll take it on first.  It concerns enormous boulders ranging in size from kitchen tables to snow-plow trucks that have a wall of smaller stones heading outward in various directions. The wall extensions are usually straight, especially if the walls are massive, but lower, less massive walls are usually more irregular, occasionally sinusoidal at the scale of yards.  I have also seen straight, well-built walls cut right across and incorporate large, apparently un-moved stones that must have lain directly in the way of the line.

Such enormous stones were were almost certainly never moved because it would take a huge amount of unnecessary effort and ingenuity to move them,  because they do not exhibit the breakage, scraping, or crushing marks that would be expected by movement, and because boulders  enveloped by walls are crossed at random positions.  Had the been moved, the stones would have been turned into alignment.   The default hypothesis is all such large stones, with or without wall attachments, are in situ glacial erratics that have never been moved.  In my four-part particle size nomenclature, they are residual stones that were left in place, rather than moved: (1) with some sort of assistance (assisted, meaning livestock, machines, levers, ramps, etc), (2) hefted with human hands (manually moved by one or two people), or; (3) handled with one hand (one-hander).

The combination of large residual stones attached to segments of walls gives rise to the appearance of tadpoles or bolts with the large head being the boulder and the long part being the segment of wall with smaller stones.  Within the CSL (Ceremonial Stone Landscape) community, some of these features are interpreted as serpent effigies with boulders for heads and walls for bodies, especially if the bodies are sinusoidal.  Some may indeed be just that. But, then again, they might not be.

Sam’s first question of how large a stone can be moved by a man and oxen is probably unanswerable because it’s only a matter of determination, ingenuity, and the number of oxen added to the team.  The Greek mathematician Archimedes (287-212 BCE) one wrote: “Give me a lever long enough and a fulcrum on which to place it, and I shall move the world.” Anecdotally, I don’t think I’ve seen an oxen-moved stone in a wall larger than 3 feet square, or about a ton in weight. Larger ones occur in cut-stone project like bridges and monuments.

With the question about residual boulders out of the way, and the one about maximum size unresolved, I asked Sam:  “Why not have another look for clues to the timing and character of movement? And, while you’re at it, measure the largest stones you know that were moved.”

He did just that, converting his curiosity into a holiday outing for his two daughters and a 60-pond dog.  By January 2, 2024, he had sent me a full report by email.  He found no obvious marks on the stones that might have been clues.  Of the five large boulders he measured from the wall, the largest had a circumference of 26 feet.  Assuming a spherical shape and “using standard formulae for arriving at volumes and a Google value of 175 pounds per cubic foot for granite,” the largest boulder would have weighed 52,000 pounds or about 25 tons. [A 26 foot circumference yields a radius of 4.1 feet, which yields a volume of 296.6 cubic feet, which yields a weight of 51,914 pounds.]  This, boulder is the broken one that ends his video below, and which I share with his permission.  My calculated weight is easily within the range of the what a large bulldozer can push, especially if the object is round enough to roll.

But when was it moved?  Based on the limited lichen cover of some of the displaced stone, I suggest less than a century.  Sam confirmed this by measuring the diameter of a sample of ten trees in the area from which the stones were moved. Using standard guess-timates, the forest was only about 50 years old.

In conclusion, I interpret that his walls are petroleum walls.  This is the term I’ve used for years to describe hybrid walls that are common throughout New England.  Those with oversized boulders either pushed in a row against an older wall or set on top of an older wall.    This makes sense given the local land use history.  A time of farming limited to livestock power creates the original wall.  And a subsequent time of forestry associated with big yellow machines capable of moving enormous stones, and caring less about how the walls end up looking.

Sam got his answer the hard way: by scratching his head, doing his homework, asking for ideas, sending his report to me, and editing the results.   The good news is that his hard way was also the fun way.  The getting out there to explore history by being a stone wall detective. And the corresponding back and forth about a mutual joy.

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Below is my commentary on the 44 second video by Sam Wadsworth. The terminology follows my book Exploring Stone Walls (NYC: Bloomsbury, 2005) and, more recently, Taxonomy and Nomenclature of the Stone Domain in New England. The digital time is in minutes and seconds.

0.01                 The boulder in the foreground is adjacent to the pre-existing wall, possibly (but not likely) having rolled off it. It also has a sharply broken edge.  The rounded boulder in the background rests atop a massive tablet, which, in turn, rests above the lower wall. The sequence is clear: wall, then tablet, then rounded boulder.

0:10-0.19          The view with the dog initially to the left shows the pre-existing wall quite clearly as a tier of assisted sized stones, surmounted by a tier of hefted- and one-hander-sized stones placed above them and tucked into void spaces.  This appears to be a normal single wall in my taxonomy.

Within this segment, at 0.15, is an spur, or out-dent of the wall consisting of a few stones directly below the large tablet. Circumstantially, it appears that these were knocked down when the tablet, or the superimposed heavier boulder, were put in place. The freshness of the joint face on the central stone in the spur suggests it was recently displaced.

0.25                 The large boulder seems to rest on crushed rock residue different from the built wall on either side.  This is a mystery because simply placing the boulder would not crush the stone like this. Where did the crushed rock come from?

0.30                 We’re back to the original wall, a single-tiered segment, likely a normal double wall, built with care, with a laid degree of order,and  with visible courses, the largest stones being at the top.

0.35                 Four large stones, two slabs and two massive boulders are placed on and over the wall, suggesting it’s built to clear stone from the near side.

0.44                 The largest stone is clearly placed in a gap on a built wall, with the flat side down. Other large stones are placed on and slightly over the wall, indicating construction, likely by a front-end loader, from the near side.

 

On November 14th, 2023, Smithsonian published an essay that has been slowly coming together for several years.  “How Stone Walls Became a Signature Landform of New England” is bringing national attention to a regional phenomenon. It’s also bringing readers from literature, history, and science to the same proverbial page.

This essay is written in a style known as long-form journalism, in this case having nearly 3000 carefully chosen words and five stunning stock photos.  In this genre, the writing moves back and forth between my own travels, Robert Frost’s poetry, facts about stone walls, New England history, and environmental issues, including climate change.

For readers lacking the patience to read such a long essay, or for those wanting help zooming in on something specific,  I decided to write a “Cliffs Notes” version of the essay that extracts and abstracts its key ideas in the order in which they appear. All of these ideas are more fully explained in the text and supporting links. Consider them “talking points” for the larger cultural conversation we’re having about the appreciation, conservation, and investigation of stone walls, and how all this can be used to educate the rising generation of movers and shakers.  For teachers, I hope that my pithy statements can be tweaked into learning objectives that could be taught outdoors in front of an old stone wall.

POETIC  ICONS.  Robert Frost’s poetry was perfectly timed to kick-start New England’s appreciation of stone walls, making them as valuable as cultural icons as they ever were as utilitarian fences.  His meditations on them at his farm in Derry, NH became the core of all his writing.

GOOD FENCES?   The building of barriers between human communities has always been a mixed blessing — a tradeoff between our evolved  needs for territorial markers and for social openness.  Do we need a clear line between us and them?

DETERMINISM.  Statistically, New England’s walls are far more alike than they are different, given the deterministic forcings associated with the landscape history of bedrock creation, glacial action, the agricultural makeover, and subsequent reforestation.  Natural, rather than cultural, factors account for most of the variation we see.

ORDER TO DISORDER.   Absent human care, all walls are fated to disappear from the landscape because they are ordered structures in a world that naturally trends toward disorder.  From low-entropy to high-entropy.  Nature ‘wants them down” via chemical and physical weathering, the growing and falling of trees, the heaving of the ground by frost, and many other factors including seismic shaking.  Nature also wants the stones more widely and randomly dispersed over the area of adjacent land and the volume of the soil.

CLIMATE CHANGE.  New England, stone walls will likely fall apart faster in the warmer, wetter climate of modernity and future projections.

LITERARY LICENSE.   Frost’s “Mending Wall,” the most famous stone wall in the U.S., is a poetic conflation of two actual walls on opposite sides of the parcel of land behind the barn at Frost’s Farm.  The better-built stack of slabs to the west that requires little maintenance, and  the tumbling row of cobbles and boulders to the east that requires constant maintenance.

HISTORIC TRANSITION.  The early 20th century was a time of landscape transition, from smaller agricultural communities to larger industrial ones, from dirt to bituminous roads, from horses and oxen to automobiles and tractors, and from open to reforested parcels. Robert Frost capitalized on the cusp of change. 

BINDING THREADS.  As a consequence of the early 20th century transition, the walls originally built to divide agricultural properties became the binding threads of a new cultural identity emphasizing the region’s shared agrarian heritage. 

SIGNATURE LANDFORM.  Though nearly ubiquitous in New England, stone walls are only locally present elsewhere in the US owing to the requirement that three limiting factors be present: hard crystalline rock like granite and gneiss; glacial till subsoils; and a family farms in need of dense fencing.

MAPPING.  New techniques involving LIDAR (Light Ranging and Detection), GIS (Geographic Information Systems) and AI (Artificial Intelligence) are accelerating progress in the mapping of New England’s estimated 240,000 miles of stone wall in New England. 

STRIP MINING.  The greater power of fossil fuels in the Anthropocene epoch has led to widespread destruction of many historic walls in New England for the purposes of commercial agriculture and for the strip-mining of stone for road sub-grade and suburban architecture.  

HABITAT:  The loss of stone walls is also the  loss of a unique habitat, and therefore a loss of biodiversity.  Ecologically, the “drylands” of stone walls are analogous to the “wetlands” of nearby floodplains, swamps, marshes, fens, and bogs.  And their ecological effects extend beyond the lines of stone.

CONSERVATION:  Ever so gradually, we are seeing a rise in legal frameworks and administrative policies devoted to the conservation and management of stone walls.  The trend toward appreciation, protection, and education is gaining ground.

 

 

 

 

 

 

 

New England residents and visitors love the region’s historic stone walls. They also love the the fact that this region’s now thickly wooded landscape is being re-wilded by creatures like bobcats.  These formerly widespread natural predators were locally exterminated because they were a threat to livestock, and those that remained avoided the open landscape of fields and pastures on former farms. But now bobcats are coming back, and stone walls seem to be a part of that story.

Over the years I’ve frequently described the ecological importance of stone walls, based on my own eyewitness accounts of chipmunks, squirrels, feral cats, foxes, human children, turkeys, snakes, and many more. But never have I seen a more dramatic visual proof of the link between animals and walls  than the 20-second video below. It shows a bobcat (Lynx rufus) using a low, bouldery stone wall first as a hunting blind and later as an elevated corridor along which it walked while scanning for prey.

 

This video was obtained and provided by Jeff Hoy.  The setting is Lee New Hampshire, a thickly wooded residential town in southern New Hampshire west of Durham. His tree-mounted, infrared wildlife camera, a GardePro, was tripped by motion at dusk on the cool, quiet, and clear solstice night of June 21, 2023.  The time was 8:35 PM.  The temperature was 59 degrees Fahrenheit (15 degrees C).  The ambient background noise was quiet except for distant traffic and the tweets of birds.

At zero seconds, the camera shows the stone-sized head of Lynx rufus moving side to side as it peered over a gap in the wall. From zero to three seconds the bobcat continued to use the wall as a low hunting blind. From three to ten seconds, it comes out of hiding and crosses the wall in order to climb to its crest.  From ten to twenty seconds it stealthily walks the wall as a transportation corridor, looking (and presumably listening) in all directions.

I found a good description of bobcat behavior and ecology provided by the Massachusetts Division of Fisheries and Wildlife.  The bobcat photo they chose (reproduced below), shows one standing next to a stone wall.  This pairing is probably no accident. I suspect that walls and bobcats go together because cats are proficient climbers that need to travel miles per day in search of prey. Walls provide an elevated and stable corridor along which the cats can move while hunting with their acute senses of sight and hearing.  Additionally, walls are common habitats for the cat’s principle prey, which are mid-sized to small mammals.    By providing both habitat for their prey and features that enhance predatory behaviors, stone walls are probably greatly appreciated by bobcats.

Moving beyond the specifics of bobcats, the stone walls of New England diversify the entire landscape, being an elevated lattice-work of stony drylands in an otherwise moist world. They are similar in composition to the rubble of rock ledges, but they are very different from ledges in being much more ubiquitous, extensive, and linked to one another.  With respect to animal behavior, they are barriers separating different habitats, corridors that guide movement, habitats for those living within the pore spaces of walls, and sites for burrows beneath their basal stones.  Each partitions the world into two realms: sunny and shaded, uphill and downhill, windward and leeward, and sites of thicker and thinner soils.

If stone walls diversify and enhance the habitat for bobcats, is the same enhancement true for other species?  For plants?  For our wildlands?

 

 

Imminently, the journal Historical Archaeology will be publishing my mini-monograph “Taxonomy and Nomenclature of the Stone Domain in New England” as an oversized journal article in what they describe as “the leading journal in the study of the archaeology of the modern era,” and “the scholarly journal of the “Society for Historical Archaeology.” Being a geologist, I have no basis for quibbling with those statements. And, as an outsider to the field, I especially pleased that they will publish my “new tool” after careful peer review of a manuscript submitted  in March 2022, accepted in October 2022, and copy-edited last winter.  With permission, I share its abstract.

The Euro-settlement of rural New England created an agro-ecosystem of fenced fields and pastures linked to human settlements and hydro-powered village industry. The most salient archaeological result was the stone domain, a massive, sprawling constellation of stone features surviving  as mainly undocumented ruins within reforested, closed-canopy woodlands.  We present a rigorous taxonomy for this stone domain  based on objective field criteria that is rendered user-friendly by incorporating vernacular typologies and functional interpretations.  The domain’s most salient class of features are stone walls, here defined as objects meeting five inclusive criteria: material, granularity, elongation, continuity, and height. We also offer a suggested nomenclature and descriptive protocol for archaeological field documentation of wall stones (size, shape, arrangement, lithology) and wall structures (courses, lines, tiers, segments, contacts, terminations, and junctions). Our methodological tools complement recent computationally intensive mapping tools of LiDAR, drone-imaging, and machine learning.

Note that I am not publishing any archaeological interpretations. Rather, I’m providing what one reviewer deemed similar to a “Munsell Soil Color Book,” an objective tool for naming and classifying that will help steer the study of relict stone walls toward science, in this case historical archaeology, which, for the Anthropocene, is also surface-process geology.  Though there was some back and forth during revision, my assertion that walls are artifacts, rather than features, survived the chopping block.  My hope is that better science will lead to better archaeology, which will lead to better environmental management. In fact, the parallels between wetland conservation and dryland (stone walls) conservation are intriguing.

This project has been a long time coming. In 2005, a preliminary taxonomy was published in my book Exploring Stone Walls, which the publisher Bloomsbury let go out of print. In 2009, I put a revised version up on this website.  Since then, I’ve been tweaking the taxonomy and naming protocols while consulting with colleagues that included three state archaeologists.  My plan was to hold off publishing in a technical journal until I felt like I had things right. That feeling never came, so I decided to take a deep breath and move forward, warts and all.

With a classification system in place, I then moved on to stone wall management and conservation,  putting together a draft set of considerations and suggestions for any organizations interested in writing more science-based regulations for protecting this precious resource.

 

 

 

 

September 2002 saw the publication of Stone By Stone: The Magnificent History in New England’s Stone Walls.  Within a week it became a steady New England bestseller. Within the year it went through several hardcover printings and earned the 2003 Connecticut Book Award for nonfiction. By 2004, it was released in paperback.  Originally published by Walker & Company, a new edition was published by Bloomsbury.  The book continues to sell off the backlist.

Throughout it all, there was no audiobook.  This changed in summer 2022 when Tantor Audio, a subsidiary of Recorded Books since 2015, saw an opportunity to publish  this “classic” as an audiobook, doing so on October 25, 2022.  I had the opportunity to read the script.

For those of you who are interested, ask your library to order the audiobook or simply purchase it from Tantor Audio.

Years ago, I was traveling through the small town of Putre in northern Chile, when I saw something astonishing.  The shape, size, and composition of its ancient stone walls in the high Andes at an elevation of 3500 meters (11,060 feet) were remarkably similar to those I’d seen in the lowland hills of interior New England. Though the inhabitants of pre-Columbian South America were raising camelids rather than sheep and cows, and though they were worlds apart from post-Columbian North American Yankees, their primitive farmstead stonework was remarkably similar.  Why?  Because the same three fundamental factors came together in time and space: the need to enclose grazing animals in heavily glaciated terrain underlain by crystalline igneous and(or) high-grade metamorphic rock.

Similarly, The Distinctively Basque Stone Shelters of California’s White Mountains, are remarkably similar to some I’ve seen in New England because the same three factors were controlling the outcome: animal enclosure, glaciated terrain, and hard crystalline rock.  This new, 2022, article by Michael R. Wing, Elizabeth H. Wing, and Amin M. Al-Jamal, describes the shelters built during the mid 19th century to protect sheep grazing in the high meadows of the White Mountains of high eastern Sierras of California. The phrase “distinctly Basque” refers not to a cultural style of construction, but to the certain historic knowledge that they were built by Basque (or adjacent French) herders.

The captioned illustration above reproduces their Figure 1, a photo of Big Stone Shelter, which located above tree line at an elevation of 3840 meters (12,600 feet), even higher than in Putre, Chile.  Its features –a glacially rounded boulder, a mix of angular and milled stones, the overall form, and the pattern of stacking– are identical to those of primitive fieldstone walls in New England.  And though this shelter is a small enclosure rather than a wall around a land parcel, New England has many such small enclosures in its formerly de-forested highlands, or as niches attached to walls.  Whether some or all of these were roofed with organic material that has since decomposed is unknown.

The similarities in expedient stone construction built by indigenous inhabitants in the high Andes, Basque herders in California Sierras, and farmers in New England demonstrate the adage that form follows function, regardless of historic or cultural setting. Such walls are ecofacts as much as they are artifacts.

Of course, the story of stone structures everywhere is much more complex than the simple connections made above. And these three connections are only a few among many.  But the conclusion is always the same. Beneath cultural overlays, the expedient architectural requirements of herding animals in rocky glaciated landscapes produces similar results.