After tramping for more than two hours through briars and brush, while scrambling around toppled trees, stumbling over rotten stumps, sidestepping an open well and slipping on moss-covered rocks, our group shuffled to a halt while Mark Starr squinted at a scribbled set of GPS coordinates.

“Have faith,” he announced, “We’re getting close.”

Our mission: Reach an unmarked, fairly inaccessible section of Pachaug State Forest in North Stonington, to view an extensive array of stone walls, foundations, and piles of rocks called cairns, some of which Starr said may date back thousands of years.

Eventually, we pushed through a low-bush blueberry thicket, crested a knoll, and gazed at a jumbled, zig-zag network of rock structures.

“If you like stones, you’ve come to the right place,” Mark said.

He identified the site as a former homestead, probably built a couple centuries ago by settlers who ill-advisedly decided to clear land in what had been a huge deposit of rocks left after a glacier receded some 12,000 years earlier.

“What kind of crazy person would build here?” Mark asked.

I had the same thought, and reacted with somewhat less enthusiasm than Hiram Bingham III must have in 1911, when he first laid eyes on Machu Picchu, the long-forgotten Inca citadel.

This Pachaug site, unlike some homesteads of similar vintage that feature defined walls and intact building foundations, frankly was a mess. Whoever lived here probably soon abandoned the rock-strewn property — a common practice among early settlers thwarted in their attempts to grow crops or raise animals in such rugged terrain, Mark noted.

We did not linger long, so tramped through more brush, and soon came upon entirely different stone structures — hundreds of cairns, some clearly visible and others partially obscured by forest understory.

Mark said he has no doubt these stone piles were built long before the arrival of Europeans in the 17th century. Unlike utilitarian walls and foundations built by colonists, he identified these Native American constructions as commemorative offerings. These included cairns, snakelike formations known as serpent walls, and distinctive piles that Mark terms “S.O.B.s,” an acronym for “stones on boulders.”

While colonial farmers had neither the time nor inclination for anything other than supporting their subsistence living, indigenous people frequently arranged rocks to pay tribute to such spiritual icons as serpents, whom they believed traversed between the living and netherworld, he explained.

Mark said the site represents a “collision of two cultures — the Native American and colonial.”

Mark is a documentary photographer and author of a dozen books on topics ranging from North Stonington dairy farms to commercial fishing to building a Greenland kayak, including his most recent volume, “Ceremonial Stonework: The Enduring Native American Presence on the Land.”

He has made stone wall research a hobby — make that obsession — spending countless hours poring over maps, hiking hundreds of miles to remote locations throughout the region, and taking thousands of photographs.

Mark and other amateur historians often find themselves at odds with academic archaeologists who insist that most, if not all, stonework was constructed by colonists.

Our excursion last week touched on this dispute, but mostly focused on the astonishing array of stones.

Rob Bareiss of New London, who shares Mark’s passion for walls, had noticed the unusual number of walls on the property while studying geographic information system maps of North Stonington. Not long ago, he asked me if I knew anything about them.

I didn’t, and referred the question to Mark, with whom I had hiked three years ago for a column published Feb. 02, 2018, “The enduring elegance and mystery of stone walls: Who built them and why at the heart of an ongoing debate.”

Mark generously offered to lead a hike of the property, and one sunny morning last week met Rob and me along the side of Denison Hill Road, where we would begin our trek. Also along were Rob’s wife, Maria, and friends who have accompanied me on numerous other outings, Maggie Jones, Bob Graham, Mary Sommer and Barry Hogenauer.

“Better bring a trekking pole — it’s pretty rough terrain,” Mark advised.

Talk about an understatement: There was no trail — we plowed through seemingly impenetrable clusters of bushes and brambles, taking more than four hours to cover only about three miles.

“I knew reaching the site was going to be a bit of work. It was a little strenuous and I would not want to take anyone there who is not prepared for a serious hike,” Rob said.

He added, “The thing that surprised me really is the extent of the site. The number of cairns, walls, wells, foundations, all in a small area, is astounding.”

Rob said he was grateful to have visited the site, but noted, “Being there raised more questions than it answered. … Now I want to know, ‘who, what, when, why’ more than ever.”

Most of us would be hard-pressed to find our way back to the location, and even Mark said he had only returned there a handful of times since first visiting it with fellow wall enthusiasts some seven years ago.

His last foray was about three years ago, and since then, overgrown brush and briars have made it even less accessible, he said.

Nature not only hates a vacuum, it also is unkind to walls, as Robert Frost observed in the poem, “Mending Wall”:

“Before I built a wall I'd ask to know

What I was walling in or walling out,

And to whom I was like to give offense.

Something there is that doesn't love a wall,

That wants it down.”

Speaking of stones, I may have had rocks in my head last week when I incorrectly reported the location of Mooween State Park. It is in Lebanon. Mea culpa.