This sublime wilderness
Author Jon Christensen writes about falling in love with the land in this excerpt from a new book of photos and essays, Nevada.
The landscape casts a rhythmic spell. You can feel it, driving Highway 50 across the middle of the state. Grinding up a steep grade to the summit. Seeing a broad valley, then more mountains, one range after another, like waves to the horizon. Coasting down the other side and out across the wide expanse.
Basin, range, basin, range. It’s hypnotic, like the sea.
“Each range here is like a warship standing on its own, and the Great Basin is an ocean of loose sediment with these mountain ranges standing in it as if they were members of a fleet without precedent,” wrote John McPhee in Basin and Range, his classic book about Nevada geology.
The ranges swarm across the state in parallel ranks. Clarence E. Dutton, a nineteenth-century cartographer, compared them to an “army of caterpillars crawling toward Mexico.” Nevada can boast that it has more mountains than any other state. In Silent Cordilleras, a 1978 survey, Alvin McLane counted 314 separate mountain ranges, 32 of which he named for the first time.
Nevada is part of the Basin and Range province, a section of the earth that is inexorably being pulled apart. Take one stride; that’s the distance that Reno and Salt Lake City, on opposite sides of this geological province, move away from each other every century. This land is stretched to the breaking point, and it is splitting apart at the seams. The mountain ranges are actually the upper edges of great tilted blocks of the earth’s crust, broken along fault lines running roughly north and south. One side of each block tilts up, becoming a range, and the other side tilts down, becoming a basin that fills with erosion from the ranges on either side.
The parallel ranges now stick out like ribs on the body of a hungry dry land. But five million years ago, when the Basin and Range topography began to form, there were no mountains between Nevada and the Pacific Ocean, and this was a moist, fertile country. About two million years ago, the Sierra Nevada began to ascend, eventually rising nearly three miles into the sky, creating a western wall that cut off the Pacific storms. The stage was set for Nevada to become a desert.
Such terrain was destined to appear impoverished, especially to eyes accustomed to the exuberant landscape of neighboring California. Even John Muir, that connoisseur of wildness, seemed to find Nevada a bit too rough for his taste: “When the traveler from California has crossed the Sierra and gone a little way down the eastern flank, the woods come to an end about as suddenly and completely as if, going westward, he had reached the ocean,” Muir wrote during a trip to Nevada in 1878. “From the very noblest forests in the world he emerges into free sunshine and dead alkaline levels. Mountains are seen beyond, rising in bewildering abundance, range beyond range. But however closely we have been accustomed to associate forests and mountains, these always present a singularly barren aspect, gray and forbidding and shadeless, like heaps of ashes dumped from the sky.”
I don’t mean to quarrel with John Muir … well, perhaps a little. For I find him a provocative foil. Like many Nevadans, I too came from California. But I stayed and fell in love with Nevada’s secrets—which are often hidden in plain sight. It just takes a while to see them.
When human beings first ventured into Nevada—sometime around 10,000 years ago as far as paleontologists have been able to discern—the climate was cooler and wetter than it is now. But as the last Ice Age ended, the weather grew hotter and drier, and the mountain ranges of Nevada became islands of moist montane habitat surrounded by a sea of sagebrush and desert scrub. Streams and springs in the desert basins became the last refuges for fish, as the waters that filled many basins in prehistoric times steadily retreated.
Now, unique communities of plants and animals survive in these isolated islands of habitat. Life is naturally precarious in this setting. Nevada is one of the top 10 states in both biological diversity and vulnerability. The state has some 300 “sensitive” animal and plant varieties that are already on federal and state lists of endangered and threatened species, or are prime candidates for listing. Some are found nowhere else.
Like the Galapagos Islands, Nevada’s mountain ranges are a good place to study evolution and the extinction of species. Thus, Nevada has landed a significant role in the study of island biogeography, perhaps the most important development in ecology since Charles Darwin’s Origin of Species.
The theory of island biogeography, first proposed by Edward O. Wilson and Robert MacArthur in 1963, provides a key to understanding not only islands in the ocean, but also habitat islands in places like Nevada (and, ultimately, most of the increasingly fragmented world that we live in). The idea is beautifully simple and easy to understand: First, larger islands harbor more species than smaller islands. This is called the species-area relationship. Second, islands that are closer to shore will be more easily colonized by mainland species. Third, each island will maintain a rough equilibrium in the number of species it hosts. If a species becomes extinct on an island, it will likely be replaced by another species, often occupying a similar ecological niche.
Edward O. Wilson and Daniel Simberloff tested the theory on small mangrove islands along the coast of Florida, and the theory held up. A decade later, in Nevada, a crucial piece was added to the puzzle, when James H. Brown discovered that boreal mammals—animals that prefer cool forests—were becoming extinct on the Great Basin’s island mountaintops. Brown searched for 14 mammals—including yellowbelly marmot, bushytail woodrat, ermine, and others—on 17 mountains. He found that the species-area relationship held true. There were 13 species on the Toiyabe-Shoshone range, which has 684 square miles above 7,500 feet, and only six species on the Diamond range, which has only 159 square miles of similarly montane habitat. But Brown found no relationship between the Great Basin’s sky islands and the Sierra Nevada and Rocky Mountains, which he considered the “mainland” and the likeliest source of immigrating species. In fact, he could find no relationships among any of the ranges, even with their closest neighbors.
Brown surmised that the mammals must have first populated the ranges more than 10,000 years ago, when the intervening valleys were more hospitable, and central Nevada was blanketed with a wide belt of trees now found only on the mountaintops. Since then, the Great Basin sky islands have become completely isolated in “a vast sea of sagebrush desert,” Brown concluded. Most of the mountains originally had a full complement of montane mammals. As they have become isolated, the islands have lost species—but they have not gained new species. There is no equilibrium, only extinction.
The presence of water makes for another kind of island habitat in the desert. Bathtub rings on the hills above desert lakes remind us that water was abundant here long ago. As the climate became warmer and drier, these waters retreated to isolated water holes.
Ash Meadows, in southern Nevada, is one such place: a low spot in the desert near Death Valley, where an underground aquifer comes to the surface in springs, lime-encrusted pools, small streams that flow all year, and swamps and seeps. The Ash Meadows National Wildlife Refuge is home to 26 plant and animal varieties found nowhere else—the greatest concentration of endemic species in the United States.
Islands are renowned as locales in which evolution struts its stuff. Fish are masters of evolution—so when fish live in aquatic islands, things get interesting real fast. Desert fishes “present one of the clearest illustrations of the evolutionary process in North America, rivaling the diversity of finches of the Galapagos Islands which first caused Charles Darwin to crystallize his ideas on the evolutionary process,” according to biologists David Soltz and Robert Naiman.
In the 13,000 years since the lake that once covered Death Valley dried up, one species of Death Valley pupfish has evolved into four different species. One of these, the Devils Hole pupfish, “has evolved in probably the most restricted and isolated habitat of any fish in the world,” according to Soltz and Naiman.
The usually aggressive pupfish are curiously peaceful in Devils Hole, perhaps as the result of isolation in an impoverished environment. Pairs mate and spawn without interference from others. The pupfish have abandoned the former ways of their kind to survive together on a rocky shelf that measures only six-and-a-half by 13 feet.
Of course, water in the desert attracts humans, too. And Ash Meadows is a sight for sore desert eyes, as Louis Nussbaumer testified in his diary in 1849: “We arrived at a beautiful valley considerably lower than we had been before and quite a warm region so that we encountered flies, butterflies, beetles, etc. At the entrance to the valley to the right is a hole in the rocks which contains magnificent warm water and in which Hadapp and I enjoyed an extremely refreshing bath.”
Unfortunately, not all of the subsequent interest in Ash Meadows has been as benign as Louis and Haddap’s bath in Devils Hole. In the 1970s, irrigation pumps threatened to drain Ash Meadows dry, and the first sign of alarm concerned the Devils Hole pupfish. Devils Hole itself was protected as part of Death Valley National Monument. But the pumps were outside the monument. In 1976, the U.S. Supreme Court upheld an injunction prohibiting pumping that would lower the water level and endanger the pupfish, which the court ruled were “objects of historical and scientific interest.”
In 1983, The Nature Conservancy bought the rest of Ash Meadows from developers who intended to build a planned community in the oasis, and Congress passed a bill making it a national wildlife refuge. Since then the refuge has been working to restore habitat. To understand just how much a little restoration can mean to an isolated species, consider this: restoring one hundred yards of a stream at Ash Meadows increased the total habitat on earth for an endangered aquatic insect by a factor of ten.
In Nevada, scientists distinguish between the hot, low-elevation Mojave Desert of cactus and creosote bush in the south and the cold, high-elevation Great Basin desert dominated by sagebrush in the north. But the two deserts blend into each other.
You can see this around Goldfield, where a band of Joshua trees marks the transition zone. I’m confident this bit of specific sightseeing advice will remain true for a while. But even though this landscape may look as old as God, it is actually a young changeling. It is a landscape on the move.
Today, piñon forests drape the shoulders of the mountain ranges in a dusty green coat all the way from Las Vegas to Reno. The piñon produces delicious pine nuts. It is the most abundant tree in Nevada, and (not surprisingly) the state tree.
But the piñon forest is a relatively recent arrival in Nevada, especially in the north. Scientists have determined this by examining pollen, seeds, and other plant material in packrat middens. (Packrats stash a little bit of everything in these caches, which are preserved for thousands of years by packrat urine.) It turns out that piñon trees were first present in southern Nevada about 10,000 years ago, and the forest has been moving north at the rate of almost a foot per day, or a football field every year.
“It’s still going north,” says Robin Tausch, a scientist with the U.S. Forest Service research station in Reno. The story of Nevada is a story of change—constant, long-term change, says Tausch. “If you want to understand that change, you need to understand history.”
Packrat middens show species on the move, appearing here, vanishing there. It is a relentless picture that conveys the grand sweep of change across the land. The changes have largely been driven by climate until the last century or so; but now the picture is getting complicated.
The pace of change seems to be accelerating rapidly. And it probably comes as no surprise that we seem to be the ones with our foot on the pedal. On a geological scale, people increased erosion in mountain canyons by bulldozing four-wheel-drive roads all over the place after World War II. We helped piñon forests spread by suppressing wildfires. And we spread weeds, such as cheat grass, by grazing cattle and building roads and power lines across the desert.
Natural forces are now amplified in unnatural ways. Wildfires help spread cheat grass, which sprouts quickly after fires and is rapidly replacing native sagebrush grasslands, fueling bigger and bigger wildfires. And unnatural forces contribute additional feedback loops: increased levels of carbon dioxide in the atmosphere contribute to global warming, and weeds grow faster with more carbon dioxide.
“In Nevada, many of our communities are global climate change canaries,” Tausch warns. “And they’re dropping dead.”
Remember those 300 or so Nevada animals and plants on the lists of endangered and threatened species? Many are on those lists because they are found only here, and in small numbers. That is their natural state—but one little push may be all it takes to send them to oblivion.
For a world throughout which people—with their cities and suburbs and roads—are turning wildlands into islands, the Great Basin offers valuable lessons. That’s not surprising, given that it is, after all, a continental landscape that began turning into islands thousands of years ago.
What are those lessons? Change is inevitable. It’s part of the landscape. And, extinction happens. That might sound harsh; but it does happen, on a large scale, over a very long period of time, and also in our own lifetimes. We can see both here.
In Great Basin National Park on the eastern edge of Nevada, one can hike through the bristlecone forest to the last remnant of the ice-age glacier that carved the cirque in Wheeler Peak. Close up, the bristlecone pine looks like a survivor. But from a wide-angle view, one that takes in deep time and island biogeography, the bristlecones look like they are clinging to their last redoubts in the Great Basin.
Bristlecone pine trees used to grow 4,000 feet lower on the mountain. Now they are found in this isolated patch. One day in 1964, a graduate student in geography cut down a bristlecone that had survived in this grove for 5,000 years. The tree’s rings can be read as a record of the climate change that drove bristlecone pines off the lower slopes and to this last stand.
As long as bristlecones survive, they will continue to record their own history. We are only a small part of their history so far. But we play a bigger and bigger role, accelerating change even as we try to figure out how to live in this changing place.
Protecting places like Devils Hole and Great Basin National Park will not guarantee the survival of the pupfish and bristlecone pines for all time, but it could ensure that people will not be directly responsible for their demise. By its very nature, understanding this land requires a close-up view of the pupfish in Devils Hole and a wide-angle view from Wheeler Peak looking west across basin and range, basin and range, as far as the eye can see.
The awful hand of fate is writ large on the face of the land. Yet life thrives in the strangest places.
Even John Muir came to love this land. It was among the bristlecones that Muir understood that the rarity of life in the desert conveys its own special value.
“But wheresoever we may venture to go in all this good world, nature is ever found richer and more beautiful than she seems,” Muir wrote in the one essay from Nevada that brims with the sublime love that he generally reserved for places other than the desert.
“And nowhere may you meet with more varied and delightful surprises than in the byways and recesses of this sublime wilderness," Muir wrote of Nevada’s mountain island forests, "scant and rare as compared with the immeasurable exuberance of California, but still amply sufficient throughout the barest deserts for a clear manifestation of God’s love."