DESERT TIME -- A JOURNEY THROUGH THE AMERICAN SOUTHWEST
Chapter 29: lost water
For a long time this was the sea. Hundreds of millions of years' worth of rivers swept bits of mountains here to lie in level deep-water layers, until all hell broke loose and this slice of continent started moving west through the Pacific, the breaking loose being that schism from our European half. This split and drift and collision of continents is known as plate tectonics. Plates meaning chunks of earth's surface, tectonics meaning construction. Which reminds me of the slow-cooked soups I used to make, the low simmer moving bits of carrot and parsley to the pot's rim as if the gas burner was the roil of planetary mantle. The science of physics and the math of chaos teach us that laws abide in all the scales of things, soup or planets. Anyway, various things have happened since.
In all things we have to work from our experience; so, watch soup doing this if you can turn your stove heat low, low enough to make the broth just "smile," as the French say; low enough and you'll have plate tectonics just fine, the soup-fat globules with their bits of carrot embedded floating on that broth as granite does on dense basalt. Throw down a peeled garlic clove and then another, pretending meteorites. Popped loose by impact, the globules split and drift and then collide as continents do, flecks of celery bobbing into fault zones, globules wrinkling in mountain ranges: Himalayas, Alps, Sierra Nevadas.
Lighter-weight oceanic islands have scraped off onto our western edge as we move across the Pacific, little globules cumulating onto the big. That meteorite plunked in a little south and east of here, the earth crust cracking with impact and, even now, shattering apart; here the seabed layers split as if by knife slice and heaved groaning up, the vast fault block of Hart Mountain tilting like a chunk of carrot. The old sea layers stand naked now, a cliff running north-northeast in southern Oregon for more than fifty miles.
Midmorning in late June: the dirt track switchbacks down that cliff, screws itself down, and the plume of trail dust drifts off behind. I stop in the scatter and ping of stone. Sneeze dust, then quiet air.
Warner Valley stretches below and away with riffles of mountains fringing to the west, dusty gold dentition, but here at the base of the cliff the valley has the perfect physiognomy of marsh. There are round shallow lakes surrounded by swirl and swirl again, clearly here main water channel and there and there twist of meander.
That marsh is no mirage, but there is no water in it. It is the skeleton of marsh. It's as dry down there as baked bone. The ponds and bayous are dust, fringed with bleached grass. The greenery is greasewood, rabbitbrush. This is alkali desert with the shape of soupy old eutrophic wetland. I blink, I conjure skillions of geese and ducks and avocets and coots and little plovers wheeling, islands of cottonwood and seething grass, and it's not hard, the shapes of marshland are graven clear as day. Only the water is gone. And everything with it.
Once I'm down I scuff my feet on a graveled shore as if I can't believe. I finger succulent needle leaves of greasewood, wishing blades of rush. I kick a rabbitbrush, which tosses, hissing like a wave. Dumb. The land is dumb, silent, flat forever. I take my chances now and turn up north on an unmarked road that is two wheel ruts through silence, dust, an immense plain.
The illusion is -- and this lasts all the hours of the afternoon that I've set sail.
Deserts are expanding nowadays at a rate of sixteen thousand square miles every year. That's all around the planet, not just here, and this mid-latitude planetary drying out argues for powers stronger than manhandling, though our misuse of desert edge can speed the process up. Grasslands can be sand dunes (as they have become in Texas) due to overgrazing, but they have been turning that way anyhow, for a while.
Climate shifts on an unthinkable scale. The hows of it are complex and how is what I'm asking, now, on this slow sailing flight through the Warner -- what is it? basin? what was it? lake! -- and big lake, too, seventy-five miles long and up to fifteen wide, with hilly peninsulas, a mountain range for islands, an eastern shore (that three-thousand-odd-foot cliff without a harbor anywhere, waves dashing the rock and all now so distant it's a misty line over there, behind, sunlit still) moving in a sea of shadowed brush the shape and color of wind-chopped wave.
Nowadays, this is a playa. That's the Spanish word for beach and is the word used for these ephemeral desert lake beds, here in North America, though playas are not rare in the scheme of things; there are more than fifty thousand of them in the world. Most of them are small. Some are not. Since water laid them down they are the flattest places anywhere on earth. They are the "pans" of South Africa, the takyrs of Asia, the sabchas of Arabia, the kavirs of Iran.
The Bonneville Salt Flats are one small part of the playa of a lake that was more than a thousand feet deep at its deepest point. It was the size of Lake Michigan. The earth's crust sagged more than two hundred feet under its weight. Ten thousand years ago it filled most of western Utah and fingered into Idaho and Nevada, and that was only its most recent high. This sometime Lake Bonneville has come and gone for the last five hundred thousand years. What's left of it nowadays is a puddlelike remnant a mere 10 percent of its former grandiose self, with a shoreline some six hundred feet lower than it was. We call this the Great Salt Lake. The level of that lake has fluctuated eighteen feet up and down since 1850, when folks began to measure. It will fluctuate some more.
Lake Baikal, the Caspian and Aral seas, the Dead Sea (once six hundred and fifty-six feet deep), Lake Chad in the southern Sahara (once seven hundred and fifteen thousand, eight hundred square miles of water), all of them are shrunken vestiges of what was. Ten and twenty thousand years ago there was a lake in what is now Bolivian desert, a lake that was larger than Bonneville. There were dozens of lakes in what are now the deserts of Nevada, California, Oregon. Lake Manly filled part of southern California to a depth of six hundred feet, it ran down the Amargosa River to the Colorado and fish came up into it then, as they had before, and then the lake dried out. Three thousand years ago it filled again. Thirty feet deep and fifty miles long, it lasted a thousand years before it dried down clear to the playa floor. The bed of Lake Manly has built up over years to a depth of five thousand feet; five thousand feet of lake-bed silts, carbonates, sulfates, salts. This is called Death Valley. In 1969 it flooded again and water lay three feet deep over eighty square miles of its old bed, one four-thousandth of its ancient self. The truth is this: these deserts, and other mid-latitude deserts, too, were full of lakes. These lakes were not small, and they've been here more than they've been gone.
The climate change that brought the glaciers south moved the temperate zone storm tracks southward, too, to fill the lakes again. There was more rain here then and it was colder, but not much of each: seven to nine inches more rain fell each year, and it was five to nine degrees Fahrenheit cooler then, then being twenty-three to ten thousand years ago. It wasn't much different, but different enough. There were glaciers in the Wasatch Range in Utah, the California Sierras. The basins between ranges filled with melt and runoff. Geologists call this centripetal drainage: all things to a common center.
Temperate lakes have outflow streams. Extra water spills on down. Here, with the added rainfall, the lakes came, and stayed.
There were exceptions. Always are. Lake Manly found the Amargosa and ran on down it to the Colorado and the sea; Bonneville burst a way through Red Rock Pass and poured unthinkable tonnages of rocks and water through the canyons of the Snake, for a period of months, before it settled down. But these are the exceptions. The whole Great Basin has no outlet to the sea. Most basin lakes have no outlet streams. Rainfall fills them, evaporation empties them. Because of this, they are acute barometers of climate. Rainfall and temperature are all. So, playas are sensitive to changes of tiny magnitude. Climate doesn't shift in a smooth curve but jiggles and wobbles -- on some trend, perhaps, like this drying trend, this present interglacial; it is, like all earthly things, irregular. Interglacials tend to last ten thousand years and glacial ages sixty thousand years or more (who defines these things? Ice advancing up there or melting seems to be the clue, glaciers being unholy sensitive as well). So Lake Warner will be back.
Meanwhile, the valley full of greasewood and sage and rabbitbrush goes on. When I have a choice I take the road that moves me north, or west, tacking toward the hardtop highway that I know is out there west of this. On the hills all around are strandlines, beaches, three of them one above the other. Three times this lake dropped, then found a new level, then dropped again. Then here's a delta where some river came.
Three antelope cross my bows, heads up and hindquarters pumping. Half a dozen sage grouse peck in the track ahead, then burst up and off with wings held level as the level ground.
Playas are the worst deserts that there are. Flat, some more alkaline than others, like oceans of baking chalk. The Black Rock and Smoke Creek and Forty Mile deserts of Nevada were, a century ago, strewn with bones of oxen and rusting rims of wagon wheels, books, Dutch ovens; they were part of the huge irregular playa of Lake Lohantan. Similar flotsam littered others, too: Great Salt Lake Desert. Fort Rock Valley. On and on.
The Spaniards navigated on the deserts with sextants and chronometers, they moved by the stars out here like mariners. I come to a fork in the track and stop, imaginary sails slatting in the stays. I fish a lukewarm Coke from the cooler and grab a bag of chips and turn windward toward the sun, there being no real choice, and any harbor anywhere out here a long way off.