Although commonly referred to as a triangle, it is really more like a three-dimensional rendering of a pyramid. The following description is quoted from the sign currently placed at the estimated original location
The original triangle was discovered just above the high-water mark in 1897 by Captain_John_Welling, William_Chappell, 'and'Fred_Blair. It was constructed with large round beach stones. The triangle was rediscovered in 1937 by Gilbert_Hedden. Erosion in the area brought on by an excavation in 1965 and severe storms caused the stones to fall into a pit on the shore.
Each side of the equilateral triangle measured 3.1m (10ft) long. A medial line of stones pointed True North (Noth star) and connected the apex to the curved line .9m (3ft) below the 'baseline'. The medial line intersected the 'baseline'(1.2m (4ft) from the west and 1.8m(6ft) from the east end. The triangle had the appearance of a very large sextant.
The point of the triangle defined by extending the third leg is oriented True North, and points directly to the location where the money pit was initially located. On OakIslandMystery.com, there is a very detailed letter (pg1, pg2) between Gilbert Hedden and Mr. R.V. Harris that attempt to explain the significance of the triangle and it's geological references. The images are watermarked with copyright, so I cannot post them here. There are also a few other diagrams of the stone triangle on this page as well.
Like many of the original structures on the island, the original stone triangle is no longer present. There are many photographs that show it, and quite a few detailed descriptions inlcuding survey records by Fred Nolan, so the location is fairly well documented, but since it is no longer there it can't be examined anymore.
There are many theories about the significance of the triangle ranging anywhere from a physical map that points to the treasure location, to a hidden Masonic sign.
Dan Blankenship believed the Stone triangle pointed not to the money pit, but to an alternate shaft from which the treasure could be located. The following is copied from the BlockHouse blog website:
In our research into the items and artifacts found over the years on Oak Island in search of treasure, we stumbled onto a possible reason for the stone triangle that unfortunately no longer exists. Rather than a marker pointing to the Money Pit as many believe, we think it may be a survey monument pointing to something towards or in the water. This is because we found just such a method mentioned in an old military surveying book a year and a half ago. To describe the method in simple terms, the apex of the stone triangle is where the surveyor positions himself, looking out along the center line towards the water. Somewhere along that line a point, labeled "T" in the example we saw, can be determined by sighting out along the two ends of the arc. Those "sight" lines will intersect the center line at some point, depending on the angles, and that point of intersection marks point "T".
Discovering this old survey method created some intriguing musings about the possibilities that point "T" could mark a flood tunnel, another hidden clue, or important landmark. Our excitement was renewed in season three of the Curse of Oak Island television show when they discovered a triangular rock off the South shore of the island. Could that be the point we thought the stone triangle might mark? Anything was possible because without the stone triangle we couldn't really determine point "T" with any degree of accuracy.
Imagine our surprise this weekend, while reviewing Dan Blankenship's field reports to Triton Alliance which he filed back in 1965. He had discovered an old shaft right on the edge of the water of the South Shore, and he wrote that the shaft was about 30 feet due south of the stone triangle. What's more is that this shaft was hidden from view. Dan wrote that it was a domed shaft buried under 12 feet of soil. He aptly called it the "Hidden Shaft". Now this is really interesting, as what better way to hide something important than to leave no indicators in the immediate area of that important spot, but create a survey monument a distance away that can be used to triangulate that spot again when needed, and only those trained in surveying would stand a chance of even knowing what the monument was for. Incidentally, it was a 17th century military surveying book we found the method in. So far, we have only found one land surveyor here in the present day that understood the triangle. Dan Blankenship investigated his Hidden Shaft in 1965 and again in 1966, forming a theory around it that involved the Money Pit shaft being a decoy, and the Hidden Shaft being the actual entrance to the Treasure Chamber in the vicinity of the Money Pit. Maybe, just maybe, the Stone Triangle was the real key to solving the mystery all of these years. Here is Dan's report for you to read:
Buried, adjacent to, or under, the so called "Money Pit" is one or two chambers, obviously filled with treasure at a depth of 171'. Elaborate engineering was envolved and a tremendous amount of labor was entailed, hence the conclusion that the treasure must be a huge one. It is doubtful that such precautions has ever been attempted before. It is my belief that the deposit is so huge that the people envolved never believed that they could keep it a secret for any great length of time so they left a "Decoy" that in itself would require a great amount of time, effort and luck for the searcher and would keep them occupied trying to figure out how to stop the water. In this endeavor they succeeded beyond their wildest dreams.
The original depositors never intended to stop the water, when they, themselves returned to recover all or part of their deposit as they needed it.
They started with a shaft directly at the edge of the water on the south shore. 30ft directly south of the triangle of stones. This shaft never came directly to the surface as they know they couldn't conceal it, if it did. So they built an elongated earth and rock dam out into the water about 40ft at which point they anchored a ship with windlasses on to facilitate the removal of earth and rock. They started their shaft (which we discovered) about 12' below the natural terrain. This shaft is about 7ft in diameter and I believe about 100ft deep. They tunneled due north about 230ft to the so called "Money Pit". There, at a depth of 175ft deep they put the bulk of their treasure in one or two chambers. This tunnel in all probability was cribbed because they had to make it safe for when they returned. All of this tunnel is below a certain band of impervious belt of blue clay which covers the island at approximately 90ft to 100ft and averages 10" to 14" in thickness. The "Money Pit" shaft was needed for an air shaft, likewise, the "Cave-in" shaft found accidentally in 1878 by Mrs. Seller when her oxen fell into a well-like hole while she was plowing.
The chambers were made water tight by 11' of puddled clay at the "Money Pit" site over which they put cement and logs. Above this is where the two flood tunnels came in. One at 110ft and the other at 125ft. The top of this water pocket was about 110ft and the bottoms at 153ft. Immediately, above this void was timber that was cut very deep into chases in the walls and upon this was supported about 7ft to 8ft of clay. Then a double layer of spruce and oak was likewise cut into chases in the walls, and it was upon this that the "decoy" treasure was placed. It must be remembered that around this earth when it was originally placed there was a ring of small stones, through which the flood tunnel water percolated and bothered searchers. All the way to the top of the shaft were placed layers of logs cut deeply into the sides. They were solely for the purpose of keeping the accumulated weight of the earth from springing the trap below the decoy. This trap was sprung about the year 1851 when they dug that shaft #6 20ft south of the M.P. and 118ft deep. At this point, they tunneled toward the M.P. and actually succeeded in getting within 20ft before it blew in on them. With the sudden release of pressure, the "decoy" treasure fell into the void that the flood tunnels filled. When we found the "Hidden" shaft October 30, 1965, on the south shore it was merely by accident. At the time we were trenching on the south shore with the hope of intercepting a suspected flood tunnel. As previously stated the top of this shaft was about 12ft below the ground level and it came to a dome shape. The top 3' to 4' was void of water and we pumped out about 5ft of water below this. We very carefully scraped off the top of the dome until we could get a pump into it and pumped it all out. At this point, careful examination proved beyond and doubt that this was done by man. Pick-marks could readily be seen in the top of this dome where the air pressure in the shaft kept the water from rising up all the way.
In digging this shaft down we found twigs, and pieces of roots 25ft to 30ft down. From 65' to 77' was five blue puddled clay, alternated with layers of course sandy red material which obviously was used to dry up the succeeding layers of blue clay. This was an ingenious water seal, the same that was put in the other end, because although the depositors didn't have to worry too much about keeping their tunnel dry (it being below the layer of impervious clay mentioned before) they did have to keep the ground from getting into their tunnel and chambers. Once we pierced this water seal we brought up many buckets of black stinking water and muck, sure proof that the tunnel and chambers have been punctured from the other end and through all the drilling done over the years. Be this as it may, I still believe we should locate this tunnel and attempt to recover the treasure by following it and cribbing as we go.
Laverne Johnson Theory
In the Book, Revealed, the Secret of Oak Island by Laverne Johnson there is a fairly detailed summary of theories surrounding Oak Island. The parts pertaining to the stone triangle are copied below.
The Roper survey did pinpoint with precision three unusual marks. They were:
- a large triangle made of stones about three hundred feet directly south of the Money Pit area,
- a large stone with a hole drilled in its upper surface, about fifty feet north of the Money Pit area, and
- a similar drilled stone more than four hundred feet approximately east of the first drilled stone.
The triangle was first mentioned in 1897 when Captain Welling pointed it out to Fred Blair. Mr. Blair had come upon the drilled stone north of the Money pit in 1895. The drilled stone near Smith’s Cove was discovered by Mr. Hedden while he was trying to connect Oak Island with the treasure map in Wilkins' book. R.V. Harris, in his book The Oak Island Mystery, described the triangle as follows:
Actually, taken from the Roper Survey the distance from the triangle to the Money Pit is approximately three hundred feet rather than two hundred feet, but obviously, Mr. Harris had been given the two hundred and ten-foot value by someone who was still trying to equate Oak Island with the treasure map in Wilkins' book. The westerly drilled stone lay approximately fifty feet north of the Money Pit, but of course when the Roper Survey was made nobody knew precisely where the original shaft lay. It was agreed that the two drilled stones and the triangle must have lain in their existing positions for a very long time, and were no doubt connected in some way with the original depositors. Until 1959 nobody seemed to connect the marks to each other. It was impossible for them to have anything to do with telling anybody how to go about recovering anything from far down in the flooded depths, so they were either ignored or treated as an unsolved mystery. Some people have suggested that the big triangle was laid down to point the way to the deep filled-in shaft when the depositor returned, but at any time since the deposit was made it was easier to find the site of the shaft than the location of the triangle, or it would have been easier if the parade of searchers had not devastated the area where the shaft had been. If some of the searchers had given more consideration to the large triangle and the drilled stone True North of the Money Pit area after the marks were first reported in 1895 and 1897 they could have come to some very interesting conclusions. They would have learned that a line running true North from the triangle apex ran through the Money Pit area and right through the drilled stone. If they had paused to consider that the triangle and the drilled stone were probably part of a code left by the depositor, they should have realized that since the depositor placed the triangle and drilled stone on a True North South line it was very probable that he placed the drilled stone True North of his shaft, and the triangle True South of it. With that knowledge they would have understood that the lost original shaft had lain along that line, and they would have had a better chance of finding it again. We have to remember that the depositor was operating in a remote area on an uninhabited Island. There were no settlers living around the shores of Mahone Bay or on the islands in the bay, and he had no reason to believe that settlers might come into the area before he could manage to return and recover his deposit. Therefore he would see no necessity for setting up some kind of intricate code to confuse somebody. Whatever he did on the Island was done to serve his own purposes. It is true enough that he did drive the long flooding tunnel out to Smith’s Cove, but he did it to seal off his deep workings, not to confuse somebody who might be so shortsighted as to think that what was buried was buried down in the flooded depths. Likewise he did not place his code marks to confuse some searcher who might come along. He placed them to direct him to the exact spot where he would dig and recover the deposit. He must have considered his deposit worth all the work he went to, but he also knew how safely he had buried it, and he made his code as simple as he could with as little room for error as possible.
As I studied the available reports in the 1950s, it becomes obvious that the marks pinpointed by the surveyor Roper, the triangle and the drilled stones, must in some way have something to do with telling where, in the high ground, the treasure must still be lying safe and undisturbed. It all seems very simple and straightforward now, but at that moment I had no way of knowing what the marks meant, or whether other essential marks had been destroyed since 1795. Harris' book stated that the vertical line or pointer of the triangle passed through the Money Pit, but it had already stated that the precise location of the original shaft had been lost. I needed a copy of the Roper Survey, and when I asked for it, M.R. Chappell very kindly sent me a photocopy of it. I soon realized that a line running true north from the apex of the triangle passed through the southern portion of the 1937 Hedden shaft and through the drilled stone north of the Money Pit area. It would be logical to assume that the original shaft also lay along that line, but I had no way of knowing where, along the line, it had lain. In time I realized that although the vertical line or pointer of the triangle pointed to the Money Pit and the drilled stone, the triangle itself was cocked in such a way that the whole triangle pointed about six and a half degrees west of true north. It was impossible to calculate the angle precisely because the triangle was simply a rough outline of irregular stones, but it did seem very likely that the triangle pointed up into the high ground toward the location of the buried deposit. Assuming that the triangle did produce a line running up into the high ground to the treasure site, there would have to be something to tell the precise bearing of that line, and also just how far along that line the treasure site lay. It seemed very possible that there were marks missing, but I could only continue to pore over the puzzle. Eventually I felt that the best way to define some point along the line from the triangle would be for the depositor to produce a second line, which would intersect the first line at the significant spot. Gradually a code was beginning to appear in which the depositor used no linear measurements, only compass bearings. Such a code would certainly eliminate the possibility of somebody making an error in measuring the length of the necessary lines. If the developing code used only degrees or angles it seemed possible that the depositor would have driven his tunnel up into the high ground on a magnetic north bearing, and that one of the intersecting lines would follow that same bearing from the deep shaft to the intersection with the line from the triangle. It was an intriguing concept, but I did not know where along the true north/south line the original shaft had been located, and I did not know what magnetic north may have been at Oak Island when the deposit was made.