It was early summer when I returned to the Potomac River bluff where I had found the rock with the carved cross. I removed the piece of rotting tree limb I had placed over it on my last visit and brushed away the fallen leaves. As the image came to view I thought how it always looked smaller and more crude than I had remembered, but just as enigmatic, with its main shaft topped by a diamond-shaped head and a line like a carpenter’s angle draped over one of the crosses’ arms.

I still had no idea what the image signified, or anything else about it, even after many visits. I’ve found plenty of fascinating clues, but none of the bits of glass, pottery, stone, and some oddball things as well, added up to anything. Each was a little story completely in and of itself. It was like astronomy before Newton.

This time, though, I was a little more optimistic. For I had come armed with an idea and some new information.

North to where? First, my idea. I took out my cell phone, flicked on the compass app, oriented the arrow north, and laid it alongside the cross. Just what I suspected: The digital age and the age of stone crosses lay in almost perfect alignment.

It was a “eureka!” moment. But while Archimedes’s flash of insight led to many scientific and technological discoveries, mine went nowhere.

What did it mean that the rock image pointed north? Why would a north-pointing rock be of any use to anyone? It’s not like people might forget which way is north, and needed a reminder. Was it a navigational aide for Santa Claus?

So as far as I could determine, my clue didn’t point to anything—except north.

Crinoid connection? Next, my new information. On my previous visit I had found what looked like a four-sided concrete post. Only the surface didn’t feel like concrete. It was smoother and more cushy. I had slipped a little piece in my pocket to check it out at home.

When I later looked at my sample under a lens, I saw that the ‘”concrete” was actually a mass graveyard of fossil marine fragments, a lot of them the familiar mini-donut segments of crinoid stems. It was limestone, probably formed sometime in the Ordovician period, around 450 million years ago. The closest limestone deposits occur about 30 miles away in the Hagerstown Valley.

Why would anyone go to the trouble of bringing carefully squared limestone posts to this place? Are they markers? Are they related somehow to the north-pointing “compass” rock?

I had already searched the web for old property markers. None looked anything like my stone. I did another thorough survey of site, hoping to find more limestone posts whose position would relate to each other in some way. I did find a couple more, but their placement appeared to be random.

Northward bound. Kneeling by the rock, I stared again at the cross, waiting for it to send me some signal. Maybe it was telling me to go north to find the answer. (Or maybe I had read too many Dan Brown thrillers.) At any rate, I set off, pushing through bushes and scrambling over rocks and logs. But aside from some broken bottles and rusty beer cans, I didn’t find anything, at least nothing that I could decipher.

See sidebar: Clues that go nowhere and beyond

This was getting frustrating. Could the rock be signaling some astronomical message? A lot of famous stone relics were created to mark astronomical events. Could my stone be a kind of mini-Stonehenge? I looked up to the heavens, but everything seemed in order—no eclipses, solstices, or meteor showers, just a Red-bellied Woodpecker hammering away at a dead snag at the top of an oak tree.

Distant rifle shot. I resumed my search along the bluff that overlooked the river. I found more glass shards and a few intact bottles, some old, some recent. Also rusted fragments of a car and a little rifle shell casing.

I carefully brushed away the dirt on the base of the casing and just barely made out “WRACO 25-20,” aka Winchester .25-20. You don’t see many of these any more. The cartridge was first introduced in1893 for the famed Winchester 1894 lever action rifle of Buffalo Bill and John Wayne fame. It hung around for years as a favorite of farmers, trappers, and pot hunters, since it’s relatively quiet and does minimal damage to meat and hides.

I  imagined what might have happened here many years ago. “John, John!” cried the farm wife. “The grey goose is gone, and the fox is on the town!”  Out ran John, just in time to see the fox—and the flapping goose—disappear over the hillside. John took a shot just to please his wife, and the crack of the rifle came back as an empty echo. The ejected casing landed where I found it.

Clues but no conclusion. Then there was the matter of that shallow pit near my stone. I slid down into the bed of leaves and broken branches, and started to feel around with my hands, hoping that copperheads by now had found cooler and moister refuges down by the river. I felt something metallic, which I pulled. It was a rusty metal strap, anchored below ground. To what? Without a shovel, I had no way of knowing.

When I later viewed the pit from a different angle I noticed what seemed to be a ring of rocks around its perimeter. Maybe it meant nothing—what else do you do with stones you find when you did a hole? Or maybe it told a story.

Before leaving I took a final look at the rock inscription before covering it over with leaves and the chunk of rotted tree limb. Clues were piling up, but so far they added up to absolutely nothing. Maybe things would start to come together on my next visit.

Or maybe I’ll never solve the mystery of the “compass rock.”

At the same time, my many hours on this bluff have taught me a great deal, things maybe even more important than the meaning of that particular rock or any of the other shreds of evidence I have found. What I have learned is this:

Here was a patch of forest overlooking the Potomac, lovely in its own right, but otherwise seemingly unremarkable. Yet, as I discovered through the bits of glass and flakes of stone, the circles of rocks and odd bits and pieces of human detritus, that spot has a conscious dimension that stretches back—who knows?—decades, centuries, maybe much longer. Even on a silent winter’s day, when nothing moves except the river, there are voices here.

A good friend of mine prepared for a visit to his doctor by compiling a thorough documentation of his medical history.  His doctor took one look at the spread sheets and the columns of numbers, and said something to the effect of, “I’m not interested in data.”

My friend—a doctor himself— was shocked. For him, as a member of a scientific and medical tradition stretching back to the ancient Hellenic philosophers, empirical evidence is the basis for knowledge. But my friend’s doctor probably already knew what specific data he would need to make a diagnosis and design a treatment. He wasn’t interested in seeking knowledge, but in solving a problem.

Unlike my friend’s doctor, I have no plan or methodology for finding the clues I need to pierce the enigma of the cross carved in stone I found on the bluff overlooking the Potomac River. For the most part, I just stumble around in the forest, happily finding clues, many of them intriguing, but none that have actually brought me closer to understanding anything significant about that odd carving. This is hardly surprising, because it would take the training and the skills of an archeologist to know what to look for and how to make sense out it, and I’m not an archeologist.

But through it all, I have found something important that goes beyond the enigmatic rock. As I write in my main article:

Here was a patch of forest overlooking the Potomac, lovely in its own right, but otherwise seemingly unremarkable. Yet, as I discovered through the bits of glass and flakes of stone, the circles of rocks and odd bits and pieces of human detritus, that spot has a conscious dimension that stretches back—who knows?—decades, centuries, maybe much longer. Even on a silent winter’s day, when nothing moves except the river, there are voices here.

Here’s a visual summary of what I’ve found.

Just a mat of dead leaves and a piece of rotted limb. But something lay underneath.

At last revealed to a curious world (at least to me).

From far back in time comes the crack of a rifle.

Its just a pit filled with dead leaves. But what about the apparent circle of stones around its perimeter?

An ordinary chunk of conrrete in an unusual place.

A mosaic of remembrances, of good times, bad health, and everyday life.

Artifacts or trash? Maybe a little of each.

Could a battered old brick mean that a house once stood here?

A scrap of metal that used to be part of– what?

A lens reveals that the post is made from a mash-up of marine fossils.

Whats a corncob doing miles from the nearest cornfield? A wandering band of Indians?

Shaped like a sharks tooth, this flake of quartzite could be an Indian scraping tool.

It looks like a rock, but hard and brittle like porcelain. I’ve never seen anything like it here or anywhere.

Cleanly cut piece of post looks like concrete, only it’s not.

Section of pipe, pounded into the ground.

A scrap of copper.

An odd metal disc with a flattened spike in the middle.

I frequently visit a particular bluff overlooking the Potomac River where a year ago I found a mysterious cross chiseled into a rock (see part I). I go there looking for clues—bits of metal, stone, pottery, anything odd or out of place—that might help to explain who made the cross, what it signifies, and why it was carved on such a humble rock in that patch of forest.

At the start of my search for answers, I was pretty confident that a couple of hours with the computer would yield at least some leads to follow. But after days of pouring over accounts of local history and thousands of images of head stones, property markers, Norse and Irish symbols, and just plain lithic doodlings, the image on my rock remained a complete mystery.

A few times I had a flash of inspiration, which quickly vanished. For example, maybe the angle hanging on the cross’s arm had something to do with Masonic symbology, as in the famous square and compass. But Masonic symbols are notably elaborate, and often encrusted in gold. Mine was simple and crude.

Or perhaps it could have been the work of a real mason, a sturdy fellow, covered with stone dust and wielding a hammer and chisel. For thousands of years, masons have carved little logos on the stones they’ve dressed, mostly so the paymaster would know who to pay and for what. I was interested to find that many of these mason’s marks feature the same diamond spearhead as the one chiseled in my rock.

Even more tantalizing, my site lies just a few hundred paces from the C&O Canal, and the stone blocks used in constructing the canal’s locks often bear such marks. That would be a convenient explanation for my mystery. Except, why would a mason saunter into the woods and put his mark on some random stone?

I also sent photos to several local experts along with an account of how I found the image and why I thought it was special. Nobody replied. Maybe they were just too busy trying to answer their own questions. ‘You found it, you deal with it,’ they probably thought as they hit the delete button.

But is it interesting?  Yes, I did find it, so of course it was special—at least to me. But how special was it really? One of my favorite cartoons by Ed Koren shows a couple walking down a beach and the woman is saying, “I do think your problems are serious, Richard. They’re just not very interesting.”

It’s true. Human artifacts are as plentiful as trash after a rock concert. In and around the Potomac River I find everything from bits of plastic to entire boats. From Sphinxes to skyscrapers, castles to cave art, to dog poop bags; mountains of rubbish and cultural treasures; people enthusiastically proclaim the Anthropocene.

This goes for rock art, as well. I have seen many famous examples: depictions of fornication rites in the Brazilian Brazil’s Sertâo, hunting scenes in Arizona, a canoe in the Minnesota wilderness, ancient tombstones in Ireland, and even a fish petroglyph right here on the Potomac.

My stone doesn’t rise to the level of such lithic icons. But who knows? We can’t judge the significance of something without knowing what its significance is.

Signs and clues. Somewhere on that bluff by the river lay the answer. So I set off on yet another pilgrimage, following the deer trails as they appear and fade in the forest, skirting rock piles and climbing over fallen tree trunks. I spotted the piece of rotted tree limb I had placed over the stone on my last visit and keeled down to clear away the blanket of leaves.

On each visit I’m struck by the rock’s modest size, particularly compared to the great boulders and cliffs that define this stretch of river landscape. If I were the chiseler,  I would have chosen one of these to carve the image. In fact, just a dozen paces from my rock stands an outcropping of great stone slabs that rise out of the forest floor like an altar. Even now they seemed to call out, ‘Hey! You with the chisel. Come over here!’

What could I find that might give context to this mysterious image? First off, there is no obvious evidence of human occupation—no crumbling foundations, no lone chimney, not even a rock wall, all common elsewhere in this forest.

I started to walk, slowly, mindfully, in widening circles, my eyes fixed to the ground. I began to find bits of glass and pottery, and then a deposit of bottles, several intact, but most shattered. One was a rich blue, several were amber colored, and many were just clear. All were glass: The age of plastic was yet to come.

Ketchup and milk. I used a stick to fish out the top of an old milk bottle with a bulge at the neck where the cream would collect. Then an intact ketchup bottle that was stamped Blue Label. As I learned later, one of the nation’s first consumer protection laws outlawed the use of the preservative benzoate. Blue Label dug in its heels, but its competitor Heinz simply added more vinegar, offered a money back guarantee, and, around 1915, Blue Label ketchup was no more. But that’s just a factoid, not a useful data point.

And then another milk bottle fragment, this one marked “Chestnut Farms Chevy Chase.” That would be Chevy Chase, Maryland, a classy community up against the DC border that for years before WWII excluded Blacks and Jews, but seemed to be OK with cows.

Then I found fragments of a concrete post—at least it looked like concrete—and near by a mostly intact one. I stuck a few pieces in my pocket to examine at home.

A sweep along the edge of the bluff yielded a tangle of fine copper wire, and then a coconut shell with the top carefully sliced off, in the manner of a human skull used for ritualistic purposes.

Circle of rocks. Nearby a group of similarly sized rocks formed a rough circle. Was it the remains of an old campfire? Anyone who has made a fire pit knows that you place the rocks one touching the other, both to contain the fire and to support a pot or a skewered fish. Here the rocks were spaced out, like the megalithic stone circles of ancient Ireland and Scotland. Could it be a minilithic stone circle?

Retracing my way back to my rock I examined a shallow, leaf-filled pit, about the dimensions of a hotel whirlpool bath. The forest is full of such pits, typically created when a tree falls and wrenches its roots out of the ground, taking a ball of earth and stones along with it. But here there were no rotting remains of a tree. Just the pit.

This was turning out to be quite a lively place. I was pretty sure that I’d find some answers on my next visit—or at least more mysteries.