ERIKA ALIN

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AU SABLE COAST

PICTURED ROCKS

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On Michigan’s eastern Upper Peninsula, a narrow strip of low-lying land extends along the water between the Hurricane River’s mouth and the light station at Au Sable Point. The strip’s eclectic mix of disorderly sandstone shelves, sandy beaches, and bluffs exists entirely at the mercy of the lake. Pummeling waves expose the sediment layers in the rock while rising and falling lake levels and migrating beaches alternately reveal and conceal small features that I often take for unchangeable and enduring. During several recent visits, high waters and waves have forced me to mostly stay on the forested trail atop the bluffs. The breeze today is light and the waters calm enough for me to walk nearly the entire one-and-a-half-mile stretch on the coast. Step after step, I look to the age-old habits of the lake to uncover the fullness of history the rocky strip holds.

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The strip sits at the eastern end of Pictured Rocks National Lakeshore, a forty-two mile band of starkly varied coastline that runs between the towns of Grand Marais in the east and Munising in the west. Archaeological finds indicate that Indigenous peoples camped and fished around bays and lagoons in the park over two thousand years ago.1 The country’s oldest national lakeshore, Pictured Rocks was designated by Congress in 1966 to protect public access to Great Lakes shorelines from growing private land ownership and development.2 Its name comes from the cliffs that rise up to nearly two hundred feet along the lake for fifteen miles east of Munising, their faces vertically streaked in bold colors left by mineral-rich groundwaters that seep out from cracks in the rock.

 

The Hurricane River, in contrast, empties into the lake roughly ten miles west of Grand Marais and takes its name from a storm that raged one summer night in 1820 when a survey expedition led by Michigan Territory Governor Lewis Cass had camped at its mouth.3 Just inland of the lake, the river flows under a footbridge and winds past an outcrop of layered tan and red-brown sandstone topped by a mop of alder and mountain ash. I turn from the river and wander east across the upper beach along a low bluff that follows the edge of the forest toward the outcrops that mark the beginning of the rocky strip. 

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By the time it reaches the end of the beach, the bluff will have risen from an initial height of around three feet to over ten feet and in the process darkened with earth and moss and grown more thickly vegetated. Similar bluffs line the coast nearly all the way to Au Sable Point, their steep upper slopes clad in fir, birch, maple, and other trees while their lower reaches either host low-growing vegetation such as mosses, bunchberries, and wintergreens or give way to short walls that drop directly onto the strip below. As the wave-cut bluff extends along the upper beach, trees and shrubs drape a shag of dark roots across its lower sands. Damp earth occasionally clings to fine webs of dangling roots, creating a pale, intricate network of thin auburn strands and bulbous clods that will likely come undone in the next heavy rain. My gaze seeks these rare, fleeting displays of crafted earth, the unexpected refinement they bring to the messy tangles of roots.  

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Once I move away from the bluff and toward the water, the sands part for a few patchy beds of cobbles and transitions to a band of pebbles that includes granites, basalts, and sandstones. While many sandstone pebbles have a uniform tan or red-brown hue, some are haphazardly mottled or adorned with elegant swerving streaks and splotches in the opposing color. The marbled rocks look like no other stones I’ve seen around the lake. A ruler-straight line divides a flat cobble into halves, the one half red-brown and the other tan. Though the colors often appear solid at a glance, on closer inspection some stones include a rich blend of hues ranging from maroon, umber, and lavender shades of brown to ivory, buff, and greenish tints of tan. Further down the beach, a thin glaze of water slips across a bare slab, turning its darker splotches a sumptuous burgundy and chocolate-brown and their lighter relations glistening casts of ochre, orange, and rose.

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Like most of the lake’s southern shore, Pictured Rocks is dominated by sedimentary rocks laid down after the Midcontinent Rift lava flows ended. Geologists separate the rocks of a region into formations, with each formation being substantial enough to be depicted on a geological map and including rocks whose shared physical characteristics make them appear distinct from surrounding rock layers. The marbled pebbles and outcrops between the Hurricane River and Au Sable Point have eroded from the Jacobsville Formation, a collection of mostly sandstone that crops out extensively along the coast from Munising west to the Keweenaw Peninsula but in Pictured Rocks mainly appears in isolated areas. Though its exact age is subject to debate, the formation had its origins in sands that eroded from highlands to the south and were deposited by streams on plains and the bottoms of lakes at the edge of the rift basin as early as around a billion years ago.4 The oxidation of iron-bearing minerals from the source rocks later likely tinted the sandstone red-brown but leached out where groundwaters flowed along joints and cracks, leaving tan streaks and splotches in the darker rock. When seen from shore, tan patches of rock that sprawl across the lake bottom are easy to mistake for loose sand. 

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I soon approach the large block-like boulders and stained outcrops that mark the end of the beach and stop by a sloping area of rock wet by runoff from the bluff. A wedge of clean, tan rock displays a distinctly grainy texture reminiscent of coarse damp sand, with loose pieces that crumble easily between my fingers. Nearby, the marbled tan-and-brown rock instead sports small teal and green-gray patches. Soft and smooth, a damp green-gray chip that I pick up disintegrates into a fine clayey paste between my fingers, with none of the hard grains of its sandy counterpart.

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I only see them in a handful of places during my walk, but wherever they appear the teal and green-gray streaks and splotches give the rock a compelling flair. Shortly after stepping onto the rocky strip, I stop in front of a low wall with a bold green-gray band sandwiched between horizontal bands of tan and red-brown rock. Like the small patches on the beach, I’ve sometimes arrived on the strip to find the band concealed by a buildup of sands. The entire lower wall is well exposed today, however, and as it gradually curves inward toward a hollow with a floor of fine sand, its damp rock glistens in green-gray, burgundy, buff, and even minor streaks of purple and blue. I quickly pull out my camera. But even on a fairly calm day like this, light swells move steadily toward shore, barely noticeable until they arc forward into small lips that run frothily landward. I frame one photograph after another, kneeling, rising, and stepping both left and right to avoid the crescents of water that rush in to lick my boots. With each move I make, I get to know the rock’s forms and colors from a slightly new angle and degree of distance.

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As in so many places on the strip, the outcrops around the green-gray band have a decidedly brooding look. Seepage from the forest has left dark, rust-colored patches on the upper wall, as well as wet wads of lime-green algae with foot-long slimy strands. The sandstone slabs and shelves that dominate the strip often extend inland for no more than fifteen to eighteen feet, and in many places far less. Sliced between the forested bluffs and water, they remain steeped in shade well into mid-morning and smell of damp, musky earth. The strip affords too little shelter for flowers or shrubs and takes its character mainly from the unpredictable temperaments of the lake. Waves strew the rock with a brew of sands, gravels, and driftwood and undercut the bluffs, leaving dead trees jutting awkwardly into the air. 

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Yet the same waters that undercut and disorder also shape the outer rock into flowing forms and keep at bay the stain that darkens nearby walls. While the strip seems to surrender in equal measure to order and disorder, I round one small point after another hoping that each new stretch will bring a display of smooth, tidy rock. Where free from gravel and stain, the outcrops more than make up for their messiness with small, clean folds that reveal the often imperceptible process by which the lake whittles down the sandstone in search of forms that can meet even the most turbulent of waters with ease.

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I eventually descend from a ledge onto a broad, low-lying shelf with a crusty top and a few gentle ripple marks shaped by ancient currents. The shelf ends in a short point to the west and as I casually peer around the point I see to my surprise an exquisitely soft, clean skirt of ochre sandstone hugging the corner of a stained wall. The skirt’s undulating folds taper inward toward the wall, adorned with fine orange, buff, brown, and rose-colored bands and a few green-gray lenses and shiny black, white, and orange granules. As I watch light veils of surf graze their base, I imagine them getting their start as ungainly bulges in the wall, slowly shedding chunks and excess grains and edges to the waves until only fluid forms remained.

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The thin bands that wrap around the folds create alternating sequences of light and dark layers, revealing how the lake’s southern shore mostly built up from the gradual accumulation of sediment deposits, with few of the massive upwellings of molten rock that laid down its northern counterpart. The layers form annual cycles of deposits, created when floodwaters early in the season dropped a layer of paler, sandier sediment that was later topped by finer, darker clay or silt that settled out after the currents had lost their force. Geologists call each light and dark sequence a couplet, two layers joined into a unit as in the rhyming lines of a poem.

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The pale, finely banded skirt brings a tender note to an otherwise untidy stretch of the strip, catching my eye largely by standing out against the tarnish and tangles of the wall above. I’m so captivated by its folds that I nearly miss the dipping wedges of sediment layers on the wall above. Called crossbeds, the wedges formed in river channels as ripples of sand gradually migrated downstream with the current. More crossbeds appear on the short point and a flatter outcrop to the east, where they instead create thin ridges that angle up the surface of the rock. It was by reading the angles of crossbeds, writes William Blewett in Geology and Landscape of Michigan’s Pictured Rocks National Lakeshore and Vicinity, that geologists determined that the Jacobsville Formation built up from sands carried by streams that flowed northwest into the rift basin.5

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As I continue down the coast, I stop in front of one small patch of clean rock after another but easily drift into complacency when the outcrops grow messy and stained. Like so many stretches of the shore, the outcrops create a training ground for learning to stay alert to the particulars that each passing step reveals. Eventually I pass a sandstone slab covered in undulating ripple marks with broad crests and gentle troughs. Spanning no more than three feet of exposed rock, the ripples were probably left by sloshing waters in a shallow lake or pool. Their crests share the ochre cast of the surrounding rock, while their troughs are colored in pale teal bands with sunken maroon dips that resemble dry pools of watercolor paint. Here and there, the teal bands instead flow into maroon bands with aqua dips, each color delineated with striking clarity.

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Yet the ripple marks sit a mere two feet from the water, on a low slab that may belong one day to land and the next day to the shallow fringe of the lake bottom. This is the first time I see them, and I again watch for incoming swells while photographing the slab, retreating each time a rush of water threatens to sweep across my boots. Summer’s high waters leave nothing to be taken for granted. As the lake continues its seasonal rise, in a few weeks’ time the ripples may vanish beneath swells or migrating gravels from a small beach to the west. The narrow strip exists in constant communion with waters that both build up and wash away its sediments and scour and shape its rocks. Long before the lake whittles them down, the forms it sculpts appear and disappear with shifting waters and sands. Slowly the lake brings forth transient forms that I may see only once, but store in memory as enduring emblems of a particular stretch of the shore.

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Sunshine bathes the strip as I sit down on a dry patch of rock and pull a park map from my pack. Pictured Rocks joins the Apostle Islands on Lake Superior and Sleeping Bear Dunes on Lake Michigan as one of only three national lakeshores in the United States. Never reaching more than six miles deep, the park is unique within the National Park Service in including lands under two different types of ownership and protection. As shown on my map, the National Park Service manages a fairly narrow Shoreline Zone, south of which sits an Inland Buffer Zone composed of national and state forests, private commercial forests, and smaller residential landholdings. The Buffer Zone accounts for roughly half of the park’s land and is intended to protect its lakes, watersheds, and coastline while allowing for logging and other forms of resource use that don’t jeopardize the area’s natural character or limit recreational access for the public.6 In 2009, nearly twelve thousand acres around Beaver Lake in the central Shoreline Zone received protection under the 1964 Wilderness Act, ensuring they would remain forever undeveloped and closed to motorized use.  

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The park serves up a richly varied landscape with upland forests of sugar and red maple, yellow birch, beech, and hemlock, wetlands of spruce, white cedar, alder, and tamarack, shrub and grasslands, and sandy glacial outwash plains of jack and red pine.7 Adding to the diversity are lakes, rivers, creeks, bogs, and marshes and a coastline that takes in both soaring cliffs and sandbanks and low-lying spits, beaches, and bays. The lake-cooled forest around the trail between the river and point features a mix of common north woods trees, including paper birch, white pine, cedar, spruce, and fir. Like many places around the lake, Pictured Rocks has been attracting ever larger crowds and the trail draws a steady stream of visitors in high summer, if still not nearly on the scale of the overlook at Miners Castle or trail to Chapel Rock and other destinations on the western Lakeshore. Fewer people, however, make their way to the point on the strip along the water. With bluffs separating me from the trail and low walls and small points creating a comfortable sense of containment, the strip feels surprisingly private and remote. 

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Shortly after putting away my map and continuing down the coast, I reach a large collection of boulders heaped onto a long arm of land that shimmies off to another point. Boulders are common on the strip, mostly scattered about the sands and nearshore waters but in a few places appearking in larger concentrations, dropped by the glaciers along with finer sediment debris that was later winnowed out by waves.8 The boulders I see now include not only some Jacobsville sandstones, but also rocks carried south from Canada or a few that appear to have eroded from the tall cliffs of the western Lakeshore. Unlike the rocky strip, the cliffs are made of younger sediments that built up between 520 and 480 million years ago in and around warm, shallow seas that flooded the continent’s interior.9 The underlying Munising Formation sits atop the Jacobsville and includes two types of sandstone, Chapel Rock and Miners Castle, each formed from sediments eroded from a different region of highlands. The overlying Au Train Formation, in contrast, built up on the seafloor from lime-rich sediments laced with the shells and skeletons of dead marine organisms. A hard cap rock that protects the cliffs from erosion, it creates the youngest formation I see during my travels around the lake.

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Several block-like boulders rest in close proximity on the strip in front of me. Most measure between four to five feet in length and one to two feet in height and have gray-brown surfaces patchily covered in stain. Yet a few feature clean blue-gray tops with yellowish margins or patches and a distinctive texture of bars, chunks, and squiggles that mostly range in length from a quarter of an inch to around two inches. Sometimes smooth and other times raised or bumpy, the tight shapes represent the remains of fossils and burrows left by small marine organisms.10 As shells and skeletons gradually piled up on the seafloor and were buried by sediments washed off nearby lands, layer upon layer built up and pressed down, fracturing and cementing the fossils into limey rock. I run my hand over the uneven surface of one block after another, thrilled to be tracing the remnants of early marine life with my fingers.

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None of the trace fossils on the boulders approximates the intact shells of corals and gastropods from the Au Train Formation that I had seen illustrated on an interpretive sign at the Miners Castle overlook. One of the best trace fossil displays sits on a low boulder with feathery arcs of water curling to and fro around its base. Countless fragments of the past may be preserved in the shape and texture of this single rock, each fragment like a memory awaiting the passage of time to bring it to the surface.

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After passing the boulders, the coast soon interrupts its northeasterly trend and makes a light dip into a sandy beach that continues all the way to Au Sable Point. Just as I had begun to get to know it, the strip abruptly changes character, defying my preference for continuity and coherence and dramatically altering the nature of my walk. I no longer have the coast to myself but share it with a near dozen other people on the beach, and instead of bouncing off sheltering walls and near points, my gaze now follows the bluff unhindered all the way to the far bend in the sands. I decide to ease into the transition by taking a break from the strip and following a weather-beaten staircase to the top of the bluff. 

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The air in the forest at the top is cool and still and the lake looks inviting and serene when seen from above. Yet the waters around Au Sable Point posed a hazard for early sailing ships and steam freighters that plied the southern shore. “Graveyard Coast” reads the caption on an interpretive sign with a map of the waters around the point by a wooden bench. According to the water depth notations on the map, the sandstone around the point creates a shallow reef which as it bulges to the northwest extends about a mile into the lake and in places sits only six feet under the surface. In addition to the map, the signpost lists the names of ten ships that ran aground near the point between 1873 and 1929, half of the twenty vessels that ultimately foundered on the reef. 

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Ships and barges loaded with lumber, iron ore, copper, and other goods began plying the south shore in growing numbers after the opening of the Soo locks on the Saint Mary’s River in 1855 connected Lake Superior to the other Great Lakes. But once ships left Whitefish Bay at the mouth of the Saint Mary’s, shallow waters and an absence of safe harbors created a treacherous eighty-mile passage west to Grand Island near Munising. The British naval lieutenant Henry Wolsey Bayfield had produced a chart of Lake Superior in the 1820s, though the chart apparently rarely made it into the hands of early captains.11 In 1872, the U.S. Corps of Engineers published a more comprehensive chart of the south shore that included detailed sailing directions from Whitefish Point to Grand Island.12 Ships, however, often traveled within sight of land and strayed onto the reef around Au Sable in dense fog or snow, or after drifting shoreward in strong northwesterly winds.13 Of the 550 known shipwrecks on the bottom of Lake Superior, over two hundred rest between Whitefish Point and Munising.14

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The map on the sign shows the location of three shipwreck remains between the Hurricane River and Au Sable Point. “Shipwreck, 1500 feet” reads a smaller sign at the top of the steps. I soon return back to the beach and walk east until I reach a collection of weathered oak beams that straddle the water and sand, the remains of two wooden freighters that mingle in the shallows.15 The thick beams create a large grid with tight rows of tall, hammered iron bolts and rusty, contorted five-inch-wide bands. The first time I passed the grid a few years ago, I didn’t see its aesthetic appeal and gave it only a perfunctory glance. Yet though crafted by human hands, the water-bleached beams, looping bands, and rusty bolts carry echoes of the forms, textures, and hues that I’ve been admiring on the rocky strip. Though I didn’t see it today, the remains of a third wreck rest near the Hurricane River’s mouth, each wreck a repository of stories exposed and concealed at the whims of the lake.   

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The sandy beach is patchily covered in cobbles and pebbles, but makes for easier walking than the rocky strip. To my side, a tall, partly vegetated sandy bluff rises toward the forest and as I continue east gradually gains a light cover of fir, spruce, and white pine. Mosses and roots bind the sands into small photogenic ledges with blueberries and twin flowers, saplings of maple and fir, and running club mosses with brightly forked strobili. I take my time composing photographs without having to watch for incoming swells and keep my camera hung around my neck while walking, as I rarely do on rocky outcrops. Yet eventually the beach begins to curve gently south and, as the light station becomes visible atop the bluff, approaches the far tip of Au Sable Point and gives way to a narrow stretch of sandstone. 

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The sandstone, in turn, soon disappears under a multitiered seawall with thick wooden ties and rock-filled cribbing. The seawall was built after the station’s hand-cranked foghorn was replaced in the late 1890s by locomotive whistles powered by heavy steam boilers, housed in a building atop the bluff near the tip of the point.16 I climb onto its broad lower tier and look northwest across the lake. Over one hundred and fifty miles of open water separate me from the Canadian shore. Though the tier provides a secure platform on a calm day like this, chunks of broken concrete mingle with boulders in the nearby water. Perched at the precarious margins of land and water, I can easily picture towering waves pounding the timbers and tearing at the cribbing under my feet, the lake doggedly trying to pry asunder the wall and sculpt the bluff in its own image. 

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Waves have undercut the lower bluff a short distance to the west of the wall and damaged the bottom rungs on a set of log steps with cable ties that leads from the beach up to the light station. I detour through the forest and then continue up the steps and arrive at the edge of a large clearing with a patchy mix of grasses and sands. To my side, a white light tower with a black lantern rises eighty-six feet into the air. When first completed in 1874, the Au Sable station provided the only light on the coast between Whitefish Point and Munising. Originally called Big Sable after the French word sable or sand, its original lamp burned lard oil. The later use of kerosene and a reflective Fresnel lens made the light visible for seventeen miles across the water.17 In addition to its tower, the station includes a two-story redbrick keepers’ residence, an oil and a foghorn building, and a boathouse and a cistern. 

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The light station sits on the National Register of Historic Places and the clearing makes blissfully few concessions to visitors: a porta potty at the edge of the forest, a drinking fountain, and a box with informational bulletins on a side wall. I follow a path partway across the grasses and stop and open a bulletin. A few journal entries from early keepers describe the “light breeze” that gathered into a “frightful storm” and the gale in which the tower “shook like a leafe.”18 The same bulletin, however, includes a black-and-white photograph from 1920 in which the tower rises into a cloudless sky and placid waters surround the dock below the bluff. Looking around the clearing, I see small wild roses, sand cherries, and clusters of blueberry and fern, scattered daisies, lance-leaved coreopsis, and other sun-loving late summer flowers. The scene is tranquil and idyllic, full of light and color.

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A few wispy clouds cast searching shadows across the lake as I stop at the far tip of Au Sable Point and turn around and gaze back at the clearing. The point is one of the few places where human structures form an intrinsic part of what draws me to the Superior shore. The light tower evokes the same reassurance as does the white tower that watches steadily over the coast from a peninsula by our cottage in Sweden. The plain, sturdy buildings, meanwhile, seem to rest with ease amid the wildness of the surrounding land. In its simple array of structures, the station answers to my longing for places where the human imprint on the shore isn’t only sheltering, but sparing, orderly, and unadorned, a mirror to the clear inner landscape for which I yearn.

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After rounding Au Sable Point, the coast dips briefly south before resuming a steady movement toward Grand Marais twelve miles to the northeast. As I look across the water from the far tip of the point, a soaring bluff of pale sediment stretches east as far as my eyes can see, a vast plateau of sand dunes at its top. The bluff is part of the Grand Sable Bank and Dune Complex and in places rises to over three hundred feet. Grand Sable has no equivalent anywhere around the lake. No matter how many times I’ve seen it before, it still creates a jarring departure from my expectations of the shore. 

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Its steep lakeside bluff forms the edge of a massive terrace of gravel, sand, and silt deposited by glacial meltwaters. Yet as impressive as the bluff is, the complex is probably best known for the sand dunes that stretch inland for about a mile at its top, creating one of the best examples of a perched dune field in the world. The dunes have built up from sands that are eroded from the lower bluff by storm waves and off-lake winds and then swept upslope toward the rim, where future winds carry them onto the plateau and sculpt them into towering forms.19 They likely began emerging around five or six thousand years ago, when a vast elevated meltwater lake stretched across the Superior, Michigan, and Huron basins.20 Reaching thirty-five feet above the present shore, the lake’s waves carved out landforms and arches along the Pictured Rocks coast and ate into the Grand Sable bluff, creating a large supply of loose sand that gathered into dunes on the plateau. 

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An intricate dance of water and wind thus sustains the dunes. Since the dunes sit high above the lake, their longterm survival depends on having enough fresh sand blow upslope to keep their surfaces unstable and prevent vegetation from spreading across the plateau. If the water level in the lake falls too low, a wide beach develops in front of the bluff and keeps waves from eroding the sands that help feed the dunes. The plateau today includes sprawling stretches of bare sand, especially toward the rim and in areas hollowed out by the wind. But it also includes ridges and hillsides covered in marram grass, sand cherry, and willow and valleys thickly forested in balsam poplar, jack pine, and other trees. From where I stand, I can see trees climbing gullies in the bluff and small hats of forest capping the rim. Yet the long lakeside slope gives little indication of the extent of vegetation atop the plateau, which researchers believe began spreading during a century of falling lake levels between 1840 and 1940.21 Fresh sands have buried forests on the plateau several times in the past, however, and could do so again.

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Landscape features rendered on the scale of Grand Sable tend to leave me at a loss, overcome by awe but unsure of how to home in. Unlike the small skirt and ripple marks on the strip, or even the shipwreck and gathering of buildings to my back, the bluff offers little sense of containment and my eyes dart back and forth in search of a place to settle. Once I pull out my binoculars, however, what from a distance looks like a fairly uniform slope of lightly sculpted sand takes on a distinctly more varied appearance. Freshly disturbed areas of soft, light orangish sand run in a band below the rim and along the beach and also descend in vertical streaks and drapes across the upper slope. Harder and more gravelly sediments, in contrast, create tight horizontal grayish lines and more irregular shapes, which join wavy lips and ridges in stretching across the bluff. Occasionally punctuating these subtler bands and areas of lighter and darker sediment are large shallow sinks and deeper craters gouged out by runoff and erosion. Were I to return regularly to Au Sable, I might notice how wandering shadows sharpen lips and ridges and drapes of loose sand flutter and re-form as wind and water continuously remake the slope. If only I seek it out, I suspect, the same potential for intimacy resides in this imposing wall of sediment as in the rocky nooks I favor.

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I eventually turn from the view and make my way back across the clearing, past the light tower and onto the trail through the forest. The sight of Grand Sable has left me yearning for the tightness of the coastal outcrops. On reaching the shipwreck sign, I follow the staircase to the beach to begin retracing my path across the sandstone strip. It’s a relief to sink below the bluffs and rejoin the passage along the lake, to know again the embrace of close walls, outcrops, and water and settle back into alignment with my surroundings. As rising and falling lake levels, shifting beaches, and swells continue to reshape the strip, I could probably walk back and forth between the river and point year after year and keep chancing on hidden layers and patterns in the rock, watching for what the ebb and flow of water reveals on the thin edge of land.