Sierra Nevada

• 1. Introduction

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  The Sierra Nevada, a range of snowy peaks in the Western United States, once earned a sharp scolding from the photographer Ansel Adams. A publication had titled a set of his photographs Parmelian Prints of the High Sierras, with that plural on the end. Adams answered bluntly: "To add an s is a linguistic, Californian, and mountaineering sin." Plenty of people who live in the range still agree with him. They say "the Sierra" and wince at anything else.

  The mountains behind that stubborn grammar run about 400 miles from north to south. They are only 50 to 80 miles wide, yet they shape the water, the weather and the history of two states. They sit between California's Central Valley and the Great Basin. Their name comes from Spanish. Sierra means a jagged range, and it literally means a saw. Nevado means snowy.

  This documentary asks how a mass of granite that formed deep underground became a wall of peaks. It asks how that wall decides who gets water and who gets desert. It asks who walked it first, what the gold seekers and loggers did to it, and why so much of it still stands protected.

  The name itself wandered before it settled. In 1542, Juan Rodríguez Cabrillo used it for a coastal range, the Santa Cruz Mountains, as a loose label for unfamiliar ranges inland. Only in 1776 did Pedro Font's map pin the name to the mountains we call the Sierra Nevada today.

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• 2. Granite and Fire

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  The oldest rocks in the Sierra Nevada are dark scraps of Cambrian age near the Mount Morrison region. Geologists call such remnants roof pendants. They are hornfels, slates, marbles and schists, found in the western foothills and east of the crest. They are the leftovers of a much older world that the granite later swallowed.

  The first Sierran granite began forming in the Triassic period, mostly east of the crest and north of 37.2 degrees north latitude. Later, in the Triassic and into the Jurassic, an island arc collided with the west coast of North America. It raised a chain of volcanoes in an event called the Nevadan orogeny. Almost all of those volcanoes have vanished. Their debris washed into the Great Valley and became much of California's sedimentary rock.

  The Cretaceous brought the main act. A subduction zone formed at the continent's edge, and the ancient Farallon Plate dove beneath the North American Plate. Magma rose in plumes called plutons, and together they built the Sierra Nevada batholith. The plutons formed between 115 and 87 million years ago. The western half came first and the eastern half followed.

  Back then, the Sierra was the western ramp of a high plateau called the Nevadaplano. Rivers cut deep canyons into it, giving it relief much like today's. About 30 million years ago, pyroclastic flows from Nevada filled the northern valleys with volcanic deposits. They kept coming for roughly 10 million years. Andesitic lahars followed and buried the northern landscape so completely that only the tallest peaks poked above a volcanic plain.

  That second round of volcanism seems to have been triggered by stretching of the crust tied to the Basin and Range Province. As it faded, about five million years ago, the rivers began scouring out the hundreds of meters of deposits and resumed their cutting. Geologists disagree about what this means. Some read the renewed cutting as proof of recent uplift. Others note that many rivers sit only 100 to 300 meters lower than their ancestors from 30 to 40 million years ago, so the northern range may have changed little.

  About 2.5 million years ago, the climate cooled and the ice ages began. Glaciers gouged U-shaped canyons across the range. Together with the rivers, they stripped away cover and exposed the tops of the old plutons. On some summits only a thin cap of the older metamorphic rock remains.

  The building is not over. Stretching in the Basin and Range continues, and it drops blocks of crust just east of the Sierra during large earthquakes. The Lone Pine earthquake of 1872 was one of them.

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• 3. Giants and Records

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  The General Sherman Tree holds the title of largest tree in the world by volume. It belongs to the giant sequoias, Sequoiadendron giganteum, which grow in groves along a narrow band of altitude on the western side of the range. No other trees on Earth are bigger.

  The water record belongs to Lake Tahoe, the largest alpine lake in North America. It sits at 6,225 feet and covers 191 square miles of clear freshwater. It fills a basin between the main Sierra and the Carson Range, a small but historically important spur that reaches into Nevada.

  The rock record belongs to the west side's glacier-scoured canyons. Hetch Hetchy Valley, Yosemite Valley, Kings Canyon and Kern Canyon are all examples. Yosemite Valley was cut by ice from granite about one hundred million years old, and it holds high waterfalls. Yosemite National Park adds granite domes, lakes and meadows.

  Heights climb steadily from north to south. Between Fredonyer Pass and Lake Tahoe, peaks run from 5,000 feet to more than 9,000 feet. Near Tahoe the crest is roughly 9,000 feet, and several peaks approach Freel Peak at 10,881 feet. Mount Lyell is the tallest in Yosemite National Park at 13,120 feet. Mount Humphreys, near Bishop, reaches almost 14,000 feet.

  Then comes Mount Whitney, near Lone Pine, at 14,505 feet. It is the highest point in the contiguous United States. South of it the range quickly gives out. The crest is almost 10,000 feet near Lake Isabella, and beyond the lake the peaks reach only about 8,000 feet.

  The slope is lopsided. From the Central Valley at 500 feet, the land rises gradually over 50 to 75 miles to crest peaks above 14,000 feet. Then the east side drops away as the steep Sierra Escarpment. This tall barrier receives far more rain and snow than the dry land around it.

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• 4. Snow and Wind

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  On the western slope, between 5,000 and 8,000 feet in the central and northern parts, precipitation peaks. Across the range, fall, winter and spring bring 20 to 80 inches, falling mostly as snow above 6,000 feet. Above 8,000 feet the totals shrink toward the crest, because moisture has already been wrung out below. Most of the land east of the crest lies in a rain shadow and gets under 25 inches a year.

  Summer is mostly dry, but afternoon thunderstorms are common during the North American Monsoon in mid and late summer. Some drop over an inch of rain in a short time, and their lightning can start fires. Winter is milder than the altitude suggests. At Tuolumne Meadows, 8,600 feet up, winter highs are about 40 degrees Fahrenheit and lows about 10.

  California lives off this snow. The snowpack is the state's major source of water and a significant source of electricity. Many reservoirs were built in the Sierra's canyons during the 20th century, and several major aqueducts carry the water to farms and cities.

  The rivers divide the range into thirds. The northern third drains into the Sacramento River, through the Feather, Yuba and American. The middle third feeds the San Joaquin, through the Mokelumne, Stanislaus, Tuolumne and Merced. The southern third sends the Kings, Kaweah, Tule and Kern into Tulare Lake, which rarely spills into the San Joaquin in wet years.

  East of the crest, the story ends differently. The Truckee River flows from Lake Tahoe into Pyramid Lake. The Carson River ends in Carson Sink, and the Walker River in Walker Lake. The Owens River runs into dry Owens Lake. No eastern river reaches the sea. Many streams from Mono Lake southward are diverted into the Los Angeles Aqueduct to supply Southern California. The same rain shadow is largely responsible for Nevada being the driest state in the country.

  The air above the range is rough. Strong westerly winds can set off the Sierra Rotor, a horizontal rotation of the atmosphere just east of the crest. The Mono winds are dry downslope gusts, most common from late fall to spring, that top 80 miles per hour. They uproot trees, damage infrastructure and make mountain passes hazardous.

  Airplanes have paid for these conditions, with downdrafts and microbursts among the dangers. A triangle with corners at Reno, Fresno and Las Vegas has been nicknamed the Nevada Triangle, after the Bermuda Triangle. Some counts put the crashes at 2,000, including the record-breaking flyer Steve Fossett. Theories linking them to Area 51 or extraterrestrials have no evidence behind them.

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• 5. Life by Altitude

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  Climbing the western slope from 1,000 to 2,500 feet, a hiker would first cross grassland, oak-grass savanna and chaparral-oak woodland, with gray pine mixed among the oaks. Gray pine goes by another name, foothill pine. Each zone above it is defined by its own climate and its own interdependent species.

  The lower montane forest comes next, at 2,500 to 7,000 feet on the west side. Its indicator species are ponderosa pine and Jeffrey pine. This zone is also notable because it contains the giant sequoia. Above it sits the upper montane forest, at 7,000 to 9,000 feet, marked by lodgepole pine and red fir.

  Higher still, the subalpine zone runs from 9,000 to 10,500 feet, with whitebark pine as its indicator. Above 10,500 feet lies the alpine region. Life there is adapted to colder weather, and nearly all precipitation falls as snow.

  The east side runs its own ladder. Because the rain shadow makes that slope warmer and drier, every zone sits higher there. The lower montane forest spans 7,000 to 9,000 feet, the upper montane 9,000 to 10,500 feet, and the subalpine 10,500 to 11,500 feet. The alpine region begins above 11,500 feet. A pinyon pine and juniper woodland, found only on the east side, fills the band from 5,000 to 7,000 feet.

  One resident needed human protection. The Sierra Nevada bighorn sheep is endangered, and the California Bighorn Sheep Zoological Area was set up near Mount Williamson in the southern Sierra to shelter it. Beginning in 1981, hikers could not enter from the 15th of May through the 15th of December. As of 2010, that restriction was lifted and the area is open all year.

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• 6. Trails and Surveyors

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  Bits of obsidian tell part of the oldest story. At Duck Pass, arrowheads of that glassy rock mark an old intertribal trade route over the mountains. Archaeologists place the Martis people in the north-central Sierra from 3,000 BCE to 500 CE. Later peoples included the Northern Paiute on the east side, the Mono and Sierra Miwok on the west, and the Kawaiisu and Tübatulabal in the south. The Washo and Maidu lived there too. Relations were predominantly peaceful, with occasional territorial disputes between the Paiute and the Sierra Miwok.

  The Spanish built missions, towns, forts and ranchos along the coast before the 1820s, yet no Spanish explorer visited these mountains. American exploration began in May 1827, when a group led by the fur trapper Jedediah Smith crossed north of the Yosemite area at Ebbetts Pass.

  In 1833, Joseph Reddeford Walker led a subgroup of the Bonneville Expedition west to find an overland route to California. His party followed the Humboldt River across present-day Nevada, climbed the Sierra, and came down between the Tuolumne and Merced drainages. They may have been the first outsiders to see Yosemite Valley. They probably saw giant sequoias too, but journals about the trip were destroyed in a Philadelphia print shop fire in 1839.

  Emigrants from the United States began arriving in 1841 by way of Sonora and Walker Passes. In the winter of 1844, Lieutenant John C. Frémont, accompanied by Kit Carson, became the first European American to see Lake Tahoe. His party camped at 8,050 feet.

  By 1860 most of the Sierra was still unexplored. The state legislature authorized the California Geological Survey, headed by Josiah Whitney, to survey it. His men William H. Brewer, Charles F. Hoffmann and Clarence King explored the backcountry of what would become Yosemite National Park in 1863. They reached the Kings Canyon area in 1864. John Muir began his wanderings in 1869.

  The mountains kept humbling the experts. In 1871 Clarence King climbed Mount Langley, believing he had summited Mount Whitney. The first true ascent of Mount Whitney came in 1873, by three men from Lone Pine on a fishing trip.

  Theodore Solomons attempted to map a route along the crest from 1892 to 1897. Bolton Coit Brown explored the Kings River watershed from 1895 to 1899. Joseph N. LeConte mapped the Yosemite and Kings Canyon areas. The mountaineer James S. Hutchinson climbed the Palisades in 1904 and Mount Humphreys in 1905. In 1912 the USGS published its set of maps, and the age of exploration ended.

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• 7. Gold and Timber

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  On the 24th of January 1848, James W. Marshall spotted shiny metal in the tailrace of a lumber mill. He was building it on the American River, near Coloma, for the Sacramento pioneer John Sutter. Rumors spread, and in March 1848 the San Francisco publisher and merchant Samuel Brannan confirmed them. He strode through San Francisco holding up a vial of gold and shouting, "Gold! Gold! Gold from the American River!"

  The New York Herald became the first major East Coast newspaper to report the find, on the 19th of August 1848. On the 5th of December 1848, President James Polk confirmed it to Congress. Soon people from around the world, later called forty-niners, flooded the Gold Country, also known as the Mother Lode. They lived in tents, wooden shanties and deck cabins salvaged from abandoned ships. Hundreds of miners would band together to build a camp and stake claims.

  The gold lay so richly in the gravel beds that early arrivals simply panned the streams. Panning could not scale up, so groups turned to placer mining. They diverted an entire river into a sluice and dug the exposed riverbed. By 1853 most of the easy gold was gone. Miners turned to hydraulic mining, aiming high-pressure jets of water at ancient gravel beds on hillsides and bluffs.

  The haul was immense. By the mid-1880s, hydraulicking had recovered an estimated 11 million troy ounces, about 340 metric tons. That gold would be worth roughly 16 billion US dollars at 2020 prices. The cost was washed downstream, as gravel, silt and heavy metals fouled rivers. As of 1999, many sites still bore the scars, because the bare earth and gravel deposits cannot support plants.

  By 1855, at least 300,000 gold-seekers, merchants and other immigrants had arrived in California. They pushed Native Americans out of traditional hunting, fishing and gathering areas. Some Native people attacked miners to defend their homes, which provoked counter-attacks on their villages. Outgunned, they were often slaughtered.

  The gold fields also created a hunger for wood. Before 1848 logging was a small business based on hand tools and ox-teams, and most of California's lumber was imported. Mining changed that. The Comstock Lode became a major center, where timber went into tunnels, shafts, buildings and fuel. In 1876 Dan DeQuille wrote that the Comstock "may truthfully be said to be the tomb of the forests of the Sierra. Millions upon millions of feet of lumber are annually buried in the mines, nevermore to be resurrected."

  In the late 1800s the industry moved west as the white pine forests of the upper Midwest ran short. The Sierra's reputation helped. In 1859, Horace Greely marveled, "I never saw anything so much like good timber in the course of any seventy-five miles' travel as I saw in crossing the Sierra Nevada."

  The Timber and Stone Act of 1878 let individuals claim old-growth tracts, which Midwestern lumber magnates then consolidated into joint-stock companies. Those firms could afford to haul timber from remote places and build sawmills beside the Southern Pacific railroad tracks laid in the 1870s. The shay locomotive and the v-shaped log flume then made the steep terrain easier to cross.

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• 8. Protecting the Range

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  In 1864 the federal government first protected Yosemite Valley. Two years later the Valley and Mariposa Grove were ceded to California and became a state park. John Muir saw overgrazing by sheep and logging of giant sequoias as problems. He lobbied successfully, and in 1890 Congress passed an act to protect the rest of Yosemite National Park. In 1906 the Valley and Mariposa Grove joined the park, and Sequoia National Park was formed. All logging of the sequoia ended then.

  Not every fight was won. In 1903 San Francisco proposed a hydroelectric dam that would flood Hetch Hetchy Valley. The city and the Sierra Club argued for ten years, until Congress passed the Raker Act in 1913 and let construction proceed. O'Shaughnessy Dam was completed in 1923.

  Lake Tahoe fared no better as a park. Between 1912 and 1918, Congress debated three times whether to protect it in a national park, and every effort failed. After World War II, towns such as South Lake Tahoe grew around the shore. By 1980, the permanent population reached 50,000 and the summer population 90,000. Development dimmed the lake's clarity, so building in the basin is now regulated by the Tahoe Regional Planning Agency.

  Recreation gradually replaced other economic activity. Funding for the John Muir Trail, which follows the crest from Yosemite Valley to Mount Whitney, began in 1915, and the trail was finished in 1938. Kings Canyon National Park was created in 1940 to protect the deep canyon of the Kings River.

  Roads became the next battleground. In the 1920s, automobile clubs and nearby towns pushed for highways over Piute Pass and other crossings. By the end of that decade, the Forest Service and the Sierra Club decided that roadless wilderness was worth more, and fought the plans. The Forest Service proposed a route over Minaret Summit in 1933. California's Governor Ronald Reagan lobbied against it in 1972, and the expansion of the John Muir and Ansel Adams Wildernesses in the 1980s sealed it off. Local businessmen proposed a Porterville to Lone Pine route in 1923. Only a roundabout road over Sherman Pass was finished, by 1976.

  The Wilderness Act of 1964 protected parts of the Sierra as primitive areas where people are only temporary visitors. Twenty wilderness areas were gradually established, including the John Muir Wilderness. Today the range holds three national parks, Yosemite, Kings Canyon and Sequoia, and two national monuments, Devils Postpile and Giant Sequoia. Ten national forests cover much of the rest.

  The numbers show the limits. The 26 wilderness areas protect 15.4 percent of the Sierra's 63,118 square kilometers from logging, development and wheeled vehicles. The Forest Service and the Bureau of Land Management control 52 percent of the land, where logging and grazing are generally allowed under federal rules.

  Threats remain. Clearcutting and thinning continue on public and private land. Grazing reaches into National Forest wilderness and can alter water flow and remove food for native species. Large wildfires such as the Rim Fire and the King Fire have raised alarm. A 2015 study tied rising California fire risk to human-induced climate change. A study spanning 8,000 years found that warm periods brought severe droughts and more stand-replacing fires. Its authors concluded that recreating the forests of before settlement may prove difficult in a warmer future.

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