The accounts told of a strange image cut into a rock somewhere below the Potomac River’s Great Falls. It had the form of a crude human face, but with a fish’s tail. Very likely it had something to do with magic and ancient rituals.

But nobody seems to know for sure what this petroglyph was or why it was made. It’s an enigma like the Mona Lisa, an emissary from a world where nothing is certain. It’s also the perfect logo for a website dedicated to Patowmack the Trickster.

I cobbled together a short account of the petroglyph and drew my logo based on sketches I had found on the web. As you’ll see, my drawing was wrong.

Even the fish glyph’s exact location is a mystery, at least to the general public. And for good reason. A vandal  with a chisel could deface or destroy this ancient image in minutes. For this reason, no sign or marker points the way. It appears on no map.  The ranger at the Great Falls Visitor’s center told me he had never seen it.

But I couldn’t just leave it at that. This is my river, and most of what makes it mine is personal experience. I had to meet this stone image face to face. I had to see it among the rocks and the rapids, hear the roar of the falls, and run my finger along the lines chiseled so long ago.

I would go on a quest, not knowing exactly what I would find. I certainly didn’t expect encounters with a government helicopter, two badly shaken young men, and a tattooed woman.

A faint trail. I learned from the Internet that the image was on the Maryland side of the river and that it faced east. A video showed a glimpse of the cliffs on the far shore of the river. I presented these few clues to Google Earth, and after several minutes of zooming and rotating, Mother Google smiled faintly and nodded. I took that as a yes.

At the Great Falls Visitor’s Center I headed down C&O Canal towpath, joining amorous couples, groups of Asians, Indians in saris, sweat-soaked runners, bell-ringing bikers, kayakers with their boats slung over their shoulders. Then I stopped, checked my bearings, and turned down a faint trail.

The trail led across the ridge of a rocky hill. I walked through a miniature forest of oaks, sycamores, and hickories, normally great and majestic trees, but here stunted by the thin soil and the powerful floods that swept down the river. My feet crunched down on a bed of penny-size shells that had been deposited by these same floodwaters. They were Asian clams, a species that arrived here only in the 1970s.

At the end of the ridge I came to a drop-off and at its base a calm lagoon. Down I went, using scraggly bushes as hand holds.

Rock magic. As I descended I paused to admire these magnificent rocks. Brutally hard, their surfaces rippled with swirls and tight folds. The rock is called metagraywacke, to me the most poetic name in the geologic lexicon.

The formation started out as “greywacke” when a mix of quartz, feldspar, and small rock fragments eroded from an ancient landmass into the ocean. An underwater current—maybe even an avalanche—swept the mix into the abyss where it mixed with fine clay and formed into sandstone. It acquired the “meta” part of its name (from the term “metamorphic,” or “change in form”) some 450 million years ago when the sandstone was squeezed and heated to near-melting deep under the accumulating sediments.

I followed the shoreline, scrambling from rock to rock as I admired the river’s ability to continue changing the earth’s crust by creating all manner of sculpted surfaces and potholes. Plastic water bottles, battered beer cans, and cigarette butts lent a contemporary touch.

I crouched to enter a tangle of flood-battered sycamore trees, their limbs festooned with dead leaves and pendants of shredded plastic that aligned with the current’s flow. I felt I was getting close.

And there it was: that very rock with the image that had become so etched in my mind. “Holy shit,” I said.

River shrine. Instead of rushing over to it, I paused. This was truly a magical spot, a tumultuous meeting place of ancient rock and water in its infinite forms. I knew why the long-ago Indian chose this spot to create his image.

On my right, the lagoon reflected the clouds and the turkey vultures tracing their lazy circles. On my left, a chute of water cascaded down a staircase of boulders and over a waterfall, then slid past a mysterious rock and concrete wall.

Before me, the falls created churning drops and rapids with names like Pencil Sharpener, Carving Board, Cheese Grater, and Pummel. Fresh their run, three kayakers surfed the standing waves. As they turned into the lagoon to their takeout spot they passed within a few paddle-lengths of the rock image. As they chatted they didn’t even glance its way.

I now crossed a little stream and stood before the object of my quest. I traced my finger along the concentric lines that formed its body, and then moved my finger up to trace its tail.

A fish tail. Something was wrong. Unlike the drawings of the image—including the one I had made myself—the tail was not a triangle. Instead it was forked. In my reading about the fish glyph I had dismissed one description of the image that claimed it represented a shad, which has a forked tail–unlike the drawings. Now I saw for myself that the glyph could in fact represent this formerly abundant fish.

Next to the petroglyph a polished depression in the rock invited me to take a seat. I imagined that the maker of the image did the same when he needed a rest from his labor.

Looking about I saw saw cobbles of quartzite, another super hard rock. They were rounded and smoothed from their trip from the distant Blue Ridge Mountains, very likely in great floods that far exceeded anything in the historical record.

I also spotted a massive block of red sandstone. It had been extracted from a quarry along the bluffs upstream from Seneca Creek in the early 19th century and then cut in a now-crumbling stone cutting mill. On its side I could make out the mark chiseled by a long-forgotten workman. The finished stone had been transported to Great Falls by canal boat, maybe to build a lock, and somehow got swept down here.

And always the trash. Glistening golf balls peeked from their hiding places under rock ledges and in the mud and debris.

Most depressing were the pockets of pulverized plastic and Styrofoam that lay between the rocks. It was just a tiny fraction of the continual stream of plastic that floats down the river and eventually into the oceans.

I felt solitude, but I was not alone. Hearing a shout I looked up at the towering rock mass that lay just downstream. Two young men wearing only gym shorts and running shoes were jumping from rock to ledge. Reaching the shoreline they waded through the lagoon. I waved to them and we chatted. “This is the best place in the whole park,” one of them enthused. But they didn’t glance at the petroglyph. Like the kayakers, the didn’t know it was there.

I thought about this. The petroglyph was officially “discovered” in 1978 by Wayne E. Clark and Peggy Leonard. But this spot has been visited for centuries after the Indians disappeared. Fishermen gathered here for the spring shad and herring spawning run. In the late 1800s crews of masons had built the mysterious wall that lay close by. Surely, somebody must have seen it. Maybe nobody was interested.

The copter descends. After the young men disappeared into the sycamore thicket I heard more shouts from the rock summit. Things were about to get exciting.

From down the river came the staccato thump-thump-thump of a helicopter. It grew louder and then roared over the rock summit, a dark silhouette against the bright sky. The copter swung low over me, the pounding of its rotors bouncing off the cliffs and making my eardrums pulsate. The terrible din wiped the petroglyph and everything else from my mind. A place of magic had become a momentary hell.

I headed for the sycamore thicket, desperate to put something—anything—between me and the copter, even it was just leaves. The downdraft from the copter’s rotors turned the branches into dervishes that flailed around me.

The copter banked and turned back downstream and I could see the spread eagle US Park Police logo on its flank. Why was it here? Was it getting a fix on a hiker with a broken leg? A kayaker who missed his roll?

Hovering over the rocky summit, the copter then dropped down so close that it almost seemed that it was trying to land. It hung there a few moments, then banked once more and its roar faded back down the river.

‘It was so crazy.’ Still not completely in control of my senses, I concentrated where I was placing my feet as I again crossed the little stream to return to my seat by the rock.

Two more young men appeared, also wearing nothing but gym shorts and running shoes. One had on sunglasses with round, purple lenses. They waded across the lagoon and sat on a rock near me.

“Thanks for scaring away the copter,” I said ironically. They were more shaken than I was. It turned out they were the object of the copter’s mission. The thundering machine had come to within just 20 feet of their heads while its crew made motions to them to leave.

“I couldn’t think, I couldn’t see anything,” said the one with the sunglasses. “The wind was kicking up everything, stones, sticks. It was all swirling around us. It was crazy.”

“It was so reckless,” said the second. “We could have slipped and fell.”

They didn’t glance at the petroglyph, and I didn’t tell them it was there. They left, and later I found the purple sunglasses lying on a rock.

Sharing a secret. It was getting late. I prepared to cross the little stream once more when I noticed a woman sitting nearby.

“Great place,” she called out.

She had a round face and an equally round body covered with a random assortment of tattoos. The ring in her lip bobbed up and down as she spoke.

“What brings you here?” I asked.  She certainly didn’t look like a hiker or an adventurer, and least of all a seeker of fish glyphs.

“It just seemed like a pretty place,” she replied.

Good for her, I thought. How great that someone with body piercings could have an appreciation for nature. I hesitated for a second, and then made my decision.

“See that rock over there?” I said pointing to the petroglyph.  “It has an image carved into it.”

“Wow! Is that a face?”

“Yes, it’s the face of a fish, and it’s looking straight at us. You can tell it’s a fish from its tail.”

Her face lit up. “That’s so neat!” she exclaimed. Thanks so much for sharing!”