Mystery surrounds Mason-Dixon marker stones


Surveyor John Andrews, right, is joined by Malcolm and Barbara Archer-Shee at the site of the Mason-Dixon Midpoint Monument near Mardela Springs. Andrews and Archer-Shee are measuring distances between old and new survey markers to use as they try to solve the mystery of six Mason-Dixon style survey stones found in western Wicomico County. (Brice Stump Photo)

Salisbury surveyor John Andrews has spent years trying to crack the mystery behind peculiar stone markers found around Mardela Springs.

They are not just field stones but rare and historically important markers almost identical to those used by the famous Jeremiah Dixon and Charles Mason team of England who surveyed the famous line in 1763-1767 settling a centuries-old dispute by the Calvert family of Maryland and the Penn family of Pennsylvania.

The boundary line established the official borders between Virginia (now part of West Virginia), Maryland and Pennsylvania and what is now Delaware, then Penn property known as “the three lower counties of Pennsylvania.”

They duo began their famous 244-mile long line at the Middle Point, a stone monument marking the 35-mile halfway point between Fenwick Island and the Chesapeake Bay at Taylor’s Island in Dorchester County, a distance of almost 70 miles. The Midpoint had been surveyed, and marked with a stone, about a decade earlier and both families agreed that it marked the midpoint of the Delmarva Peninsula.

Mason and Dixon set stones every mile between the south-west corner marker of Delaware, just north east of Mardela Springs, to the point where the line touched the arc of a 12-mile radius circle centered in New Castle, a distance north of about 81 miles. Called the Tangent Line, it became the boundary line that ran north and south between the point along the arc and the Middle Point, the official division between Maryland and Delaware.

The mathematician-surveyors used special 4-foot stone markers, quarried and shaped in England, that are roughly 12-by-12 inches thick and 4 feet long, to mark every mile of the Tangent Line. Special “crown stones,” of the same dimensions and bearing the armorial crests of the Penn and Calvert families, were set every five miles.

Years ago, country folks report finding one-mile stones in the hedgerows, woods and fields. One is now located underground in a church parking lot in Mardela Springs. At least six stones have been found.

“None of them are on the Tangent Line or Transpeninsular Line,” said Andrews. “Surveyors and historians have been studying this mystery for years and can’t explain how they got here and why they are where they are.”

Although mile markers were also supposed to have been placed on the 35-mi-e long Transpeninsular Line between the Midpoint and Fenwick Island, none were set. Only the five miles markers were placed on the line, and two of them, mile markers Nos. 25 and 30, are lost.

A stone marker, noting the location of the 15-mile spot, was not set because it would have been

situated in the Cypress Swamp of the Pocomoke River.

These five-mile markers are not similar to the Mason-Dixon stones used on the Tangent Line.

Even though Mason and Dixon did not officially resurvey the Transpeninsular Line as part of their

commission to establish a line between Maryland, Pennsylvania and Virginia, by 1840 maps identified that line as part of the over-all Mason Dixon survey route.

Some folks and businesses on either side of line refer to it as the Mason-Dixon Line.

Yet all the “mystery stones” found are almost identical to the Tangent Line mileposts, which bear a carved “M” for Maryland one side and a “P” for Penn or Pennsylvania of the other.

“It’s been thought these stones were ‘extras’ and were left here after the survey was completed and the mile markers were set,” Andrews said.

Yet in their journals, neither Mason or Dixon mention any “extras” being discarded, nor do the records indicate that 10 or possibly 12 markers were simply discarded and up for grabs by farmers wanting free quality line markers.

A single post could have been broken by farmers wanting two substantial pieces of worked stone as boundary markers, but neither of the six posts so far found have been broken.

Weighing almost 500 pounds, each post was transported to various sites around Mardela — some miles away — and all those found had been set upright.

Peculiar, too, is the strange circumstances of the stones at the Midpoint, housed under a pavilion along Route 54. Inside a gated enclose are four stones, yet by the time Mason and Dixon concluded their work in 1768 and returned to England, there were just two stones, one set by Colonial surveyors in 1761 marking the halfway point from Fenwick Island to the Chesapeake Bay and the largest marker bearing armorial crests on all four sides, the so-called Midpoint Monument, set in late 1768.


A third stone appeared for a number of years, then disappeared and has reappeared. Another was placed at the site by 1950 and still remains at the site.

“What we are looking for a old photos of the monument site, taken between 1920 and 1960,” Andrews said. “We don’t have to borrow them, but we would like to copy them on the spot. Just takes a few seconds.”

Also important are stories folks may have about the Midpoint stones as well as those associated with Mason and Dixon stones with the carved M and P.

“We are hoping someone can tell us where others are or even share photos or stories,” Andrews said. “People should know that any stones found do not belong to any federal, state or private agency, so they shouldn’t worry about questions of ownership. If they are on private property they belong to the landowner, pure and simple.”

Just how many Mason and Dixon mile markers are out there is a mystery, according to the surveyor.

“If folks will help, we are trying to establish some kind of uniformity to their placement on a map. I don’t think all these mystery stones were or are necessarily on property lines,” said Malcolm Archer-Shee, of near Easton, who is working on the mystery stone project with Andrews.

Archer-Shee once served as District One Survey Party Chief which handled Maryland Highway Administration survey work in Somerset, Wicomico, Worcester and Dorchester counties. Respected for his meticulous work, Archer-Shee is also trying to solve the mystery as to why the known mystery stones are set where they are.

Richard Wright, and Ridgely Morison, who live near the Midpoint Monument, are also hoping the mystery will be solved. Their families gave farmland to Maryland and Delaware to allow the building of the pavilion and park at the site.

Morison was instrumental in having the large Mason-Dixon marker reset at the site when vandals broke it off its base in the late 1970s.

Wright, 93, said he can’t explain how marker stones have come and gone at the site over the years.

Andrews and Archer-Shee believe the original Colonial stone and the Mason-Dixon stone at the site have a role in the relevance of the locations of the mystery stones.

“When I was a boy, people didn’t think much about the stones, nobody paid them any attention I never thought they would be as famous as they have become,” Wright said with a chuckle.

If you can share photos, stories or even the location of a stone on your property, Andrews is hoping you will contact him by calling 410-726-2306.

Contact Brice Stump at

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