Utah's Arches National Park was one of the first places I photographed in the western United States. Compared to New England’s forests and shorelines, where I grew up, this part of the continent felt overwhelming. Even after initially viewing the more prominent arches, I found it difficult to comprehend that these extraordinary formations were created through erosion. Inspired by its name, I hiked up the steep slope under Landscape Arch to an...

Thunderclouds often form over Southern California's Mt. San Jacinto, the highest peak in a range that abruptly rises 10,000 feet from its base on the west side of Palm Springs. Clouds stream eastward from the crest of the mountain chain, though storms drop almost no rain on the city, as it lies in the mountain’s rain shadow. On the evening this photograph was taken, the smooth lenticular cumulonimbus cloud dissipated as the sun sank below the...

Hundreds of millions of years ago, sediment collected in an alluvial plain formed along the seam between the North American and African continents, which cemented into sandstone and shale. Later, the region rose to become the Appalachian Mountains. As the range uplifted, the rock cracked, creating a break – the Delaware Water Gap – through which the Delaware River carved its course to the ocean.

This photograph was taken at the top of...

The weather in the Utah Canyonlands undergoes a seasonal shift in early October. Monsoons have long since ended, and a northwesterly flow brings in fall’s first “blue norther.” Several years ago, during the October trip when I captured this image, a cold front came through eastern Utah’s Arches National Park, providing the first rain to dampen the dust and clear the air of wildfire smoke. That evening, the remnants of a towering cumulonimbus...

The remains of a fallen tree nourish other plant life in Western Washington’s temperate rainforest. Botanists call the now-horizontal trunk of this toppled snag a "nurse log." It provides seedlings with a moist surface of decaying wood and shelters their early growth from pathogens in the soil below.

It takes about as long for a nurse log to decay as it did for the tree to mature. What appears to have been a western hemlock fell about a...

Thirty years ago, while trekking south-central Utah's Escalante River, I accidentally discovered the Golden Cathedral. At the time, it was unnamed, but it later became a popular destination. Of equal height, width, and depth—about a hundred feet in each direction—its character transforms throughout the day through subtle shifts in the sunlit reflections off the walls and pond.

Over time, water carved out sedimentary rock to form this...

The first snow dusts the shadowed slopes of central Colorado's Rocky Mountains in early autumn, portending the changing seasons. When I visited this incredible alpine valley in the heart of the mountain range, the aspen trees had begun to turn and would reach full color in a couple of weeks.

The valley where I took this photograph and the mountains surrounding it were formed from an ancestral mountain range's metamorphosed and uplifted...

A promontory on the south shore of eastern California's Mono Lake hosts a collection of tufa towers once formed beneath its surface. A few hundred years ago, when the lake was deeper, underground mineral springs bubbled up from its bed, chemically interacting with the saline water to build the limestone tufa formation in this photograph.

One of North America's oldest extant lakes, Mono Lake, was created three-quarters of a million...

A 1.7-billion-year-old boulder rests, precariously balanced in the streambed of central Colorado's Roaring Fork River. It is composed of oceanic sediment mixed with molten lava that metamorphosed into granite several miles underground through eons of heat and pressure. After one billion years of uplifting and erosion, the rise of the Rocky Mountains surrounding the Roaring Fork River unearthed this ancient layer of granite.

The deeply...

The Sauceda Mountains in south-central Arizona straddle the eastern section of the Barry M. Goldwater Bombing Range, which the public can explore with a permit. The Air Force trains air crews in fighter jets that twist and roar across the sky, practicing air-to-ground combat on its 1.7-million-acre range. Rare hikers, including my group, explored an otherwise untrammeled wilderness.

On the slopes of its low mountains, which cross arid...

A conifer seedling grew on the edge of a lake terrace undercut by waves and winter ice. In time, the young tree lost its footing and fell into the lake. Its roots were still anchored to the shore, and its crown and branches landed on the waterlogged trunk of a previously fallen tree. Over time, the top of the young, flexible tree shifted its growth upward. Then, later, as its submerged roots rotted, the tree died.

Though the details of...

On this autumn day in coastal Maine, streams had diminished in flow, causing a beaver pond to sink. A smoky scrim of dust and organic detritus arose to cover its surface. Bodies of waters like this are commonplace in Maine, where a quarter of its land is comprised of wooded swamps, bogs, marshes, and meadows, several times the amount of wetland in the other five New England states combined.

When I lived in Maine, exploring the...

Over 30 years ago, I took a steep hike from the banks of Southeastern Utah's San Juan River, to the top of a small volcanic crater. Here, 25-30 million years ago, super-heated water erupted at near hypersonic speed through a fissure deep within the earth, dragging rock debris upward and venting into the atmosphere. This geologic phenomenon is known as a diatreme.

Often, diatremes leave shafts that become hardened from the heat of the...

Southeastern Oregon's 9,733-foot Steens Mountain trends 50 miles north-northeast, formed by a wrinkle in the tectonic forces that have shaped much of the western United States's Basin and Range country. In June 1831, Hudson Bay Company fur trader John Work described this mountain as "covered with snow," leading to its first name, the Snow Mountains. For most of the year, the crest's treeless subalpine tundra is covered in deep snow and,...

Ninety million years ago, a rising sea flooded low-lying parts of western North America, dividing the continent with a seaway connecting the Arctic Ocean and the Gulf of Mexico. A thick seam of blue-gray fossil-rich silt and mud accumulated in a part of this shallow ocean that once covered the area that is now the Utah/Arizona border. Its weight pressed clay into stone, uplifting a mile above the ground and creating a plateau.

This...

"No other canyon in North America combines the depth, narrowness, sheerness, and somber countenance of the Black Canyon of the Gunnison," wrote geologist Wallace Hansen. The Ute People hunted and gathered plants along its rim, but there is no evidence they entered the canyon. They regarded it as a sacred, dangerous place and, perhaps, a portal to the underworld.

Black Canyon of the Gunnison National Park is tucked away in an otherwise...

The Oregon coast—including its cliffs and promontories along Cannon Beach—was formed by 15-million-year-old volcanic lava flows originating in eastern Oregon. They coursed west along the Columbia River's route to the Pacific Ocean coast, well west of today's shoreline. Erosion and rising sea levels left remnants of the former headlands as steep-walled islands that we now call sea stacks.

The first people to inhabit this region arrived...

In the Athabasca River Valley of western Alberta’s Rocky Mountain Range lies a field of glacial drift made up of limestone and sandstone gravel, stones, and boulders dropped off the retreating toe of the Athabasca Glacier a century ago. Among the rocks rests a boulder, once whole, now split perfectly in half on the slope of a terminal moraine. This kind of clean break can happen after a glacier has retreated, the ground may subside from...

Southern Utah’s San Juan River once snaked across a nearly flat plain. Over time, the river’s current cut into its banks, crafting an increasingly sinuous channel. Later, while tectonic forces raised the level of the land by several thousand feet, the river continued to follow its original course. Carving through the emerging plateau, it dug deeper into the underlying bedrock to create an entrenched meander. This geologic feature has occurred...

The geologic complexity of the Grapevine Mountains along the California/Nevada border was first described in 1875 by geomorphologist G.K. Gilbert, who noted, "the strata are greatly disturbed and dislocated… " Cutting across the strike of the mountain range, Titus Canyon is an anomaly in an extraordinarily dry desert; the mightiest force in carving this canyon is the desert's rarest commodity, water. In the deepest reaches of the canyon where...

Cradled in the dunes behind Coast Guard Beach once sat Henry Beston's cabin where he wrote his 1928 classic "The Outermost House," a poetic diary of a year lived on Cape Cod's eastern shore. This evening, the intertidal flats, fed by water draining into the ocean from the beach face, filled small depressions. Sand ripples, formed by the continuous rhythmic motion of the waves, were rounded on their crests by the ebbing water, with each tide...

Wading through a pool shaded by National Canyon’s deep recesses near its confluence with the Colorado River, I hoisted myself and helped my hiking companions up over the chockstone shown in this photograph. We scrambled past it only to find deeper water and more chockstones in a narrow passage between the steep limestone walls. It was useless; this was as far as we could travel without climbing gear, which we did not bring along – or imagine...

Second Beach, along the central Pacific coast of Washington State, is a popular destination for Olympic National Park visitors. Even when busy, it is so long and wide that beachcombers may feel a sense of solitude, especially when the tide is out and one can roam the enormous expanse of untrampled tan, red, and black sand between the forest and the waves.

Geologically, Second Beach is built of mélange rocks, a mixture of sand, gravel,...

On a hike to Barachois Falls near the fishing port of Rose Blanche on Newfoundland's rugged south coast, I felt the sun occasionally break through, warming the open country as it vied with cold, moist winds. Rising off the nearby Atlantic Ocean, the fog spread across the rolling barrens. The broader vista darkened and obscured; I focused on the details of the landscape, stopping at a pond where swaying sedges caught my attention, their tips...

The lightning strike shattered bark, exploded wood, and the cottonwood grove caught fire. A day later, on my first evening visiting southeastern Utah’s Dugout Ranch, I slept outside, and was often awakened by the sounds and light of the burning trees. I arose before dawn to record the spectacle as flaming branches loudly fell onto the ashened ground. Posing no threat to spring's rain-soaked pasturelands, the smoldering trees...

A once-lofty conifer, the tree trunk shown in the foreground of this photograph, had most of its canopy snapped off a century ago. Photographers Carleton Watkins and Ansel Adams photographed the falls in 1861 and 1948, respectively, when the enormous tree was still alive. Long since bare of needles, it stands erect in death, overlooking Vernal Falls like an ancient sentinel.

Though named Vernal Falls in 1851, it was originally called...

In south-central Washington State, 14,411-foot Mt. Rainier's commanding presence captivates observers up to 300 miles away. That is, when it is cloud-free. Moisture from the Pacific Ocean condenses on the persistently cloud-covered flanks of this volcano. As a result, the mountain is "out" only one day in four and is one of the snowiest places on the planet.

Taken from the Emmons Glacier Overlook on a rare cloudless morning, this...

In December 1960, writer Wallace Stegner wrote to a friend what has since been called his “Wilderness Letter.” In the letter, he describes the southeastern Utah desert as a place that “can be a means of reassuring ourselves of our sanity as creatures, a part of the geography of hope.” He references the desert country around Caineville as “a lovely and terrible wilderness, such a wilderness as Christ and the prophets went out into; harshly and...

NASA researchers once tested space suits in Skylight Cave – a central Oregon lava tube – as it was thought to be representative of “extraterrestrial” caves on the Moon, Mars, and other planets. This earthly cave once offered shelter to indigenous peoples, and every winter, it hosts hibernating Townsend's long-eared bats. On the June morning this scene was captured, I was greeted by other unexpected visitors: a couple having wedding pictures...

Dante's View is a mountain terrace a mile above Death Valley near California's eastern border with Nevada. Below lies Badwater Basin, the lowest point in North America and the site of the world's hottest recorded temperature (130 degrees Fahrenheit). On a cloudless day, one can see the 11,000-foot Panamint Range across the basin and, on exceptionally clear days, glimpse the peak of 14,505-foot Mount Whitney, the highest point in the...

On this quiet morning, the mudflats where John's Canyon meets the San Juan River displayed a fresh layer of sediment as a flood from the previous day abated. A radiant stone and stippled boulder – having long ago tumbled out of the canyon's mouth – rested in an elliptical pool. Its tranquil water luminously mirrored the pre-dawn light reflecting off an 800-foot-tall cliff. The scene struck me as a dreamlike set piece.

Southeastern Utah...

When I first drove into the badlands, I left behind the Midwest's verdant plains to unexpectedly arrive in a haunting land of crumbling clay. As I explored, I began to realize its extraordinary and surreal barrenness was changing my way of perceiving it. That afternoon, a thunderstorm had formed over the Black Hills and moved east across this desolate country. The horizon was notched by pinnacles and buttes upon ground broken by ravines and...

Where the sea meets the beach, waves funneled into this cave. During the brief lull between waves, I entered to understand what a sea cave looks and feels like when the ocean rushes into it. A surging swell raised the water level; waves rinsed the layer of barnacles attached to the lava walls. Through the cacophony of countless air bubbles bursting, the waves gave voice to their journey's end. As the tide retreated, my footprints were erased,...

Buckskin Gulch is a classic slot canyon: long, narrow, deep, visually stunning, and unnervingly claustrophobic. It traverses the rugged desert country bordering Utah and Arizona, part of a broader region of uplifted red rock called the Colorado Plateau. The upraised sandstone fractured, forming joints that periodic flash floods carved to create extraordinarily narrow chasms.

I made this photograph near the beginning of the gulch, where...

As we rafted down southern Utah's San Juan River, we saw that a flash flood had raced down the river ahead of us, originating from one of its side canyons after a late summer storm. Once the river receded and the silty flow settled out along the riverbanks at the entrance to Oljeto Canyon, the desert air began hardening the fresh blanket of mud.

As we exited the river boats, mud stuck to our sandals and squirted around our feet,...

The Columbia River Gorge marks the boundary between western Washington State and Oregon. A fjord-like 80-mile stretch of river is inhabited by 90 waterfalls. Almost all of them are on the Oregon side, where the topography favors their formation. Over millions of years, hundreds of lava flows built layers of basalt rock that tilted away from the river to form the sheer cliffs, over which the water descended.

Latourell Falls is the...

Grotto is a term often used to describe a natural cave or cavern, though the word derives from something human-made. A richly decorated structure built by the Roman Emperor Nero soon after the burning of Rome in 64 A.D. had, over time, sunk underground only to be rediscovered in the 15th century. Upon viewing, it was considered very strange; something uncovered from the “underworld” and was called a grottesca – literally “of a cave.”...

Standing at the edge of eastern Utah's Dead Horse Point, I survey a 270-degree view east, south, and west across the grand expanse of red rock country and down 2000 feet through geologic time, and the lithified layers of mud and sand from an ancient era, when the North American continent was located near the equator.

Over eons, these sedimentary stratums were deposited in oceans, windblown deserts, freshwater lakes, streams, and...

Amid Washington State's Olympic Mountain Range, the Hoh Rainforest shelters ancient stands of coniferous and deciduous trees, most notably along its Hall of Mosses Trail. One of the best-preserved temperate rainforests in the world, its stable ecosystem is maintained by a steady flow of moist air off the Pacific Ocean. It delivers abundant rainfall of twelve feet annually in the cooler seasons and ample sunshine in the drier summer.

It...

Horseshoe Falls is the largest of the three waterfalls forming Niagara Falls along the Canada–United States border. Ninety percent of the Niagara River, or an average of 3000 tons of water per second, flows over the 167-foot height and the half-mile-long arc of Horseshoe Falls.

Niagara Falls was created when the Niagara Escarpment was exposed after the retreat of glaciers at the end of the last ice age. The escarpment is a cliff face...

Walking the shoreline of Pebble Beach gave me the opportunity to loiter along the intersection of three states of matter, with the calm Pacific Ocean to my left, the ragged wall of colorful sandstone to my right, and the vaporous sky above. Ambling the shoreline invited a close examination of this extraordinary environment where water, earth, and air converge to craft the landscape’s contours and details, inspiring a state of wonder that left...

Bryce Canyon is renowned for its colorful, awe-inspiring formations. Their creation began with ancient floods periodically depositing massive amounts of fine-grained sediment over millions of years. Under the weight of its layers, the sediment lithified into rock. The earth's mantle moved and uplifted much of the intermountain west to high plateaus before eroding this part of southwestern Utah to reveal an otherworldly dreamscape.

The...

In 1753, George Washington passed by this location, traveling along the Venango Path, an ancient portage trail carved by the Seneca, Onondaga, and Cayuga People and migrating herds of bison. French Creek, named by Washington, marked the western edge of early French and English expansion. In the 19th century, as homesteaders journeyed to the far west, they detoured around this heavily forested region of northwestern Pennsylvania, which...

Located along Washington State’s Pacific coast, Rialto Beach is covered by cobblestones and sand relentlessly assaulted by encroaching and sometimes ferocious ocean erosion. Here, a lone Sitka spruce leans into the onshore winds and waves, which have scrapped away at its lower trunk, leaving bark only on the upper part of its leeward side.

Sitka trees grow along a narrow coastal strip from northern California to southern Alaska....

Gushing out the cliff's recess, Spouting Rock's unusual waterfall emerges from the sedimentary limestone that underlies this region of central Colorado. The stream then flows into Hanging Lake, situated just below the falls, and, from there, feeds into the nearby Colorado River. The sound of the falls blends the low, rumbling echo of the stream flowing through the crevice's opening and the high-pitched splash of water striking its rocky...

Two hundred million years ago, the supercontinent of Pangaea contained the earth's entire landmass. An early variety of pine trees grew along waterways in the region of Pangaea that is now Arizona, where flooding, wind, and death felled whole forests of these 200-foot-tall trees.

'Chinle' means "flowing through." The Navajo Tribe uses this word to describe soils washed down from Arizona's fertile highlands into its otherwise arid...

Orion, the renowned hunter of Greek mythology, was first written about in the 8th century B.C. Though mortal, Orion was reputedly the son of the sea god Poseidon. A fateful story tells of his affection for Artemis, daughter of Zeus and Goddess of the Moon. However, Artemis' jealous twin brother Apollo tricked her into killing Orion. Apollo challenged Artemis – an expert archer – to aim for a head bobbing far out to sea, claiming the swimmer...

A young spruce tree falls from the riverbank into a crook in the Roaring Fork River, still green with needles. Over time, I’ve watched its needles brown and thin. Eventually, bark and branches will fall off or be stripped by weather and current. Its trunk will finally settle onto the channel’s stony floor slowly, possibly over many years.

This river originates beneath the nearby crest of the Sawatch Range of central Colorado’s Rocky...

Accumulations of deep snow coating Four Mountain – located in western Washington State – cascade down its steep slopes, amassing on a slanted plain at the Mountain's base. This buildup formed a permanent snowfield under which meltwater streams have carved icy, banquet hall-sized caves.

The hike to the caves traverses a terrain littered with the remains of winter's avalanche-downed Pacific Silver Firs (usually found at higher elevations...

Black Dragon Wash takes its name from a nearby pictograph that, as once outlined in chalk, resembled a dragon. Later, it became apparent upon closer inspection that some passersby carelessly encircled what initially appeared to be a dragon but was, in fact, several figures painted in the ancient style of hunter-gatherer tribes from two thousand years ago. Nevertheless, the misnomer became the adopted name of this wilderness canyon within...

A lichen-freckled granite boulder held the evening's fading light. Deposited on a granite bench that rims the shoreline of Deer Isle on Maine's midcoast, it rests uncertainly, transported here by an ancient glacier. When the climate warmed and the weighty ice retreated, the land bulged, fracturing its bedrock. Seeps sprung from cracks in this terrace, leaching minerals, staining its surface, and breaking the bedrock into thin, irregular...

When I first saw this rock glacier from the valley floor, it looked like a scree slope, flat and stationary. Further up the trail, as I photographed this scene from above, I realized its appearance was much different, exhibiting the same shape and sense of movement as an ice glacier. However, unlike the smooth exterior of ice glaciers, its furrowed surface resembled pale, desiccated skin.

Rock glaciers form in a manner similar to ice...

Sitka spruce inhabited glacial moraines left from the last ice age along the Pacific coast from California to Alaska. They thrive on frequent morning fog and are unfazed by clouds of salty wave spray from onshore winds. This species welcomes the fury of late fall's blustery storms and winter's ample rains. Though the low sun of December's solstice does not penetrate the thick stands easily, the trees continuously grow from year-round...

Carved deep within the cavernous fold of a plateau bordering both sides of the Green River is a remote canyon that traverses eastern Utah’s desert. “We pass through a region of the wildest desolation,” wrote John Wesley Powell, thus naming the canyon during a historic 1869 river expedition that eventually carried him and his crew through the Grand Canyon.

Rock Creek begins at the 9800-foot crest of the Roan Cliffs, cascading down to...

“Their appearance was exactly that of the sea in a storm, except as to color, not the least sign of vegetation existing thereon,” wrote U.S. Army Lieutenant Zebulon Pike about the Great Sand Dunes on an 1807 expedition he led through the Rocky Mountains.

Dune fields often form where the earth’s tectonic plates move apart, creating depressions in the earth’s contours known as rift valleys, such as southern Colorado’s San Luis Valley....

The Skeena River is one of North America's largest free-flowing (undammed) rivers. Its course runs from the interior of northern British Columbia to its coast, passing through the world's largest intact temperate rainforest, the Great Bear Rainforest.

To the native nations that share this region, "the word 'Skeena' means "water from cloud," a place of abundant rainfall and persistent cloud cover. Geographically, they rely on a mild...

Granaries are storehouses for safely preserving seeds, beans, and grains away from animals, insects, disease, and floods. Typically built from timber, stone, and clay, evidence of their construction goes back over 11,000 years, and they continue to be used worldwide today.

The Nankoweap Granaries were built around 1100 AD by members of the Ancestral Puebloan culture who cultivated food in a significantly different environment. Today,...

Extending far seaward from Maine’s eastern coast, shifting tectonic plates and ancient erosion exposed Schoodic Point's bedrock. Granite fractured into irregular blocks, broken seams filled by molten flows that cooled into black basaltic veins.

After the last ice-age glaciers retreated, the rock shelves again rose and stabilized. Today, granite benches flank the ocean, its flat-topped terraces tilting down to the North Atlantic's edge....

Cradled in a lava bowl, Alex Creek flows over a 40-foot moss-covered outcrop, draping it like a luminous veil as spring-fed water spills into a shallow pool. Echoing off its basaltic walls, one can hear the waterfall before it comes into view, hidden in the cleft of an old-growth forest of Douglas-fir, western hemlock, and big-leaf maple.

Spirit Falls is a dreamlike refuge between the crest of the Cascade Range and the Willamette Valley...

Above the historic silver mining town of Creede, Colorado, an 11,000-foot plateau skirts the San Juan Mountains of southern Colorado. One summer day in the 1980s, I hiked from an abandoned sawmill through ancient groves of blue-green spruce. The La Garita Wilderness I entered appeared to float above the world. La Garita is Spanish for "lookout," aptly describing a wondrous panorama of snowmelt creeks deeply incised through the gentle terrain...

The moon arched across the night sky, and from its sweeping light, this six-hour film exposure rendered a soft glow to the island and lake. The Northern Paiute call the island "Wono" – the name for their woven cone-shaped baskets. In 1843, government expedition leader John Fremont gave the island and the lake their current names when he wrote in his diary, "We encamped on the shore, opposite a very remarkable rock in the lake … from the point...

Newfoundland’s rugged and exposed south coast contains numerous fjords, bays, and harbors supporting small and widely separated villages. These “outports,” only accessible by fishing boats and coastal steamers, date back to the 1500s and earlier.

Historically rich in fishing grounds, over-harvesting during the latter half of the 20th century collapsed the industry in 1992. One effect was the emigration of inhabitants from smaller...

Summers in western Washington State challenge the usual perception of the Pacific Northwest as a perpetually cool, wet place. The weather is warm and dry from Independence Day to Labor Day. Perfect for building spider webs so that by the end of August, they abound everywhere in the forests, including this park near Seattle.

Some plants become enveloped by cobwebs. And very different types of spiders can produce them, the smallest being...

Horseshoe Canyon shelters one of North America's most significant rock art sites. Beginning around 8000 BC, hunter-gatherers from the Desert Archaic Period seasonally visited this canyon and created pictographs (paintings on rock walls) between 1000 BC and 1000 AD. Using a mixture of blood, vegetable, and mineral compounds, they depicted hundreds of figures as tall as eight feet and as small as six inches along a 200-foot wall within this...

Redfish Lake is the headwater of central Idaho’s Salmon River, which flows into the Snake River and continues to the Columbia River and Pacific Ocean. Up until the late 1800s, 4,000 sockeye salmon annually returned to the lake — their birthplace, 900 miles from the ocean — to bear the next generation of sockeye. It is the longest such pilgrimage in North America.

During their run, splashing sockeye used to keep ranchers awake at night....

Upon a wind-swept knoll above the fishing outpost of Green Point on Newfoundland’s west coast, graze a hardy strain of sheep first introduced to the island province in the 16th century. Derived from the Border Cheviot breed common to the Scottish and English borderlands, this local stock is shorn and set out to pasture in the spring and their lambs sent to market in November as the blustery winter sets in.

The field of summer forage...

Four thousand feet above the Pacific Ocean on the northwestern side of Kaua'i lies a deeply furrowed plateau, the remains of a caldera rimmed by Wainiha Ridge. Lava flows and accumulations of sediment have eroded since Kaua'i’s volcanic origins millions of years ago. In truth, this ridge is nearly 20,000 feet above the ocean floor. A relic of an ancient seamount — the oldest in the Hawaiian island chain — these highlands are covered by a...

Few other plants are so readily identified by place as the saguaro in Arizona’s Sonoran Desert. Though it looks like a tree, it is in fact a cactus. The tallest plant in this desert and largest cactus in the United States, it typically grows to 45 feet and weighs 4000 pounds. Saguaros take a century to mature and after that may live as long as another century.

The cactus’ imposing size, its arms gesturing to the sky, and the fact that...

Fifteen thousand years ago, what is now western Montana, lay beneath a 2000-foot-deep lake formed from meltwaters that became impounded after exiting an ice sheet that covered large parts of North America. Twice a century for two millennia, an ice dam formed and then, under building pressure from rising water, periodically ruptured sending cataclysmic floods across parts of Idaho and Washington State into the Columbia River Gorge. Driving...

On this early dawn around summer solstice, the sun rose behind the western face of Devils Tower. The architecture of this 1300-foot structure was first formed underground from molten volcanic rock that slowly cooled from liquid into hardened polygonal columns made of rare and exceptionally durable phonolite porphyry. Long buried beneath layers of sedimentary rock, the erosion of the softer sandstone, shale and gypsum around the structure, in...

A couple of days prior to making this photograph, the San Juan River that traverses southern Utah suddenly surged. Its color turned from grey-green to red. The flood’s origin was from northeastern Arizona’s reddish-brown sandstone formations. Beginning as a cloudburst, a dense muddy torrent raced down Chinle Wash entering the San Juan River at its confluence. Later, downstream in the quiet backwater of Moonlight Wash, rippling patterns of mud...

A lone Sitka spruce grew atop this sea stack, protected on its windward side by the crest of a 50-foot pillar that is the eroded remains of land uplifted by the movement of tectonic plates. On this spring day along Washington’s northwest shoreline, the earth was quiet and the seas calm; a 314-year reprieve from the most recent of violent earthquakes and tsunamis that shaped this region, and a seasonal break from winter’s heavy surf that...

Prior to the last ice age, French Creek flowed north to Lake Erie and then to the Atlantic Ocean. Later, retreating glaciers deposited a thick layer of rock debris in the northwestern corner of Pennsylvania. Its terminal moraine blocked the creek and forced it to reverse course and flow south joining the Allegheny River, which runs into the Ohio and then Mississippi River, eventually draining into the Gulf of Mexico. The creek remains one...

In 1988, a wet spring was followed by a drought that led to the driest summer in the history of Yellowstone National Park. Fueled by dry tinder, lighting, strong winds, and, to a lesser extent, the activities of outfitters and woodcutters, over 50 separate fires merged to create an out-of-control conflagration that burned 800,000 acres of the northwestern corner of Wyoming.

Dozens of elk and other animals were consumed by fire, as was...

Concealed deep within the canyons of northern Arizona are the remains of well-preserved dwellings sheltered beneath an overhanging cliff of Navajo Sandstone. Over the period it was inhabited, 150 living spaces and granaries were built on a ledge high above the canyon floor, securing the community from enemies and inclement weather. At first glance, it’s difficult to distinguish the village from the alcove within which it sits; its...

Along Nova Scotia’s northwest coast, the steep slopes of Cap-Rouge’s French Mountain meet the southern shore of the Gulf of St. Lawrence. An extension of the Appalachian Mountain chain; Cape Breton’s tablelands are built upon the most ancient known rocks in Canada’s Maritime Provinces.

Skirting its coastline, in 1932 the once rocky Cabot Trail was replaced by a paved scenic highway encircling the cape. Beginning in the early 19th...

During late September, as nights lengthen and scrub oaks lose their chlorophyll, their leaves turn to rich hues of yellow, red and brown lending a surreal aspect to this austere desert. Cradled within the northern slopes of Utah’s rugged La Sal Mountains, Castle Valley is an unexpectedly level basin. Three hundred million years ago, this place was along a shoreline that built up thick layers of salt later buried beneath heavy deposits of...

Seven thousand, seven hundred years ago, southwestern Oregon’s 11,000-foot Mt. Mazama erupted. Legends from the Klamath people carry first-hand accounts of the collapse of the mountain, laying waste to much of the surrounding area, depositing a deep layer of volcanic ash and, in its aftermath, creating within its volcanic caldera a 2000-foot-deep lake of pristine clarity. In this early morning of late fall, the low morning sun reflects off...