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Yosemite Nature Notes 46(2) (1977)


Yosemite Valley at night
[click to enlarge]

The Illuminated Valley

by Larry Huggins

The night-time view from Glacier Point is unforgettable. Three thousand feet below lies the deep, grassy valley of Yosemite, sanctum sanctorum of the Sierra, lit up like a Christmas tree. An engulfed cathedral, the valley lies immersed in the glow of nearly 100,000 watts of artificial incandescence.

“The night, like clean water and the wolf, is getting away from us,” states Barry Lopez. “Our cities are filled with children who have never seen the milky way . . . The comfort and mystery of a night full of stars and nocturnal creatures are eroding before us. The stars have become the victims of artificial lights; the dark woods at midnight are a victim of neglect.”

The night is not only disappearing from our large cities, but from our National Parks as well. In Yosemite Valley, as darkness falls upon the campgrounds, hotels, meadows and forests, the sun’s light is replaced by the glow of countless streetlights, utility lamps, shaded pathway lights, spot and floodlights, illuminated signs, decorative architectural lights, fluorescent service station tubes, and the omnipresent headlight glare of the machines they serve, the automobiles.

The meadows at night are especially vulnerable to disturbance by the automobile. Bridalveil, El Capitan, Leidig, Sentinel, Cook, Ahwahnee, and Stoneman Meadows are all bordered by roads. Like fencers’ swords, the twin headlights criss-cross, high beams feinting and flashing across the darkness of the meadows throughout the night. Every night. Everywhere in the Valley. There is no place on the Valley floor which is more than a fourth of a mile from a road.

Where headlights don’t penetrate, the bright streetlights do. The developed, eastern part of the Valley sports several hundred poorly shaded streetlights and parking lot lights. These lights are on a special 1,000 volt circuit; each bulb produces 1,000 lumens. An ordinary 75 watt household bulb, by comparison produces 900 lumens.

Pervading the depths of the torested areas are the hundreds of tree-mounted utility lights that illuminate every corner of Curry Village and the multi-use Yosemite Lodge area. At the Lodge, more than 300 guest units have individual light globes outside their doors. At Curry, the number exceeds 150.

Ten-watt decorative lamps abound at Curry Village. Nearly 100 of these bulbs decorate the sign that welcomes visitors to “Camp Curry.” Stoneman House has nearly 300 bulbs decorating its eaves, spaced one foot apart. The Gift Shop and Information Booth are adorned with 110. Thirty-six eight-foot flourescent tubes blaze over the gas pumps at the Lodge Service Station. Imagine them as one single 288 foot light bulb which converts 7,000 watts of electricity into brilliant artificial daylight. It seems probable that, with a large enough telescope, one could detect its glow from the moon.

This is not to suggest that the concessioner is alone in the extravagant use of outdoor illumination. The Park Service campgrounds, warehouse and maintenance areas, employee housing compounds and administrative buildings contribute countless thousands of watts of artificial glow to the Sierra night.

A four thousand watt Quartzline bulb brightens the entire south wall of one stone building where the metal letters VISITOR CENTER impress their importance on predawn passersby.

A survey by this writer found that in Yosemite Valley, outdoor lighting alone consumes nearly 100,000 watts. Left on all night, these lights consume nearly 1,000 kilowatt hours per night. That’s approximately 90,000 kilowatt hours consumed during the six summer months. If one were to add to this all the indoor lighting which, because of glass walls or inadequate window shades and curtains, penetrates outdoors, these figures would likely be doubled.

It’s difficult to calculate how much all this costs. Sunshine Electric Company, the euphemism applied to the Park Service hydroelectric generating and transmission system, provides the bulk of Valley electrical power needs. Two generators, installed in 1918 and powered by the Merced River, produce their rated capacity of 2,000 kilowatt hours. When demand is great, they operate at 25% more than rated capacity. Ironically, electric fans are used to cool the generators to prevent over-heating when they are operated at peak levels.

Some of this output is sold to the concessioner, some to employees as household electricity. Still other amounts are sold to Pacific Gas and Electric Company during times of least demand. The rate structure is exceedingly complex. There are three different rate schedules in effect and countless circuits on separate rates for billing purposes. If one were to arbitrarily set a value on the energy consumed, say a value of three cents per kwh (a rate which is about midway between the highest and lowest values assigned by the Park Service), the cost would reach $250,000 for outdoor illumination during the summer months alone.

So far as can be determined, there is no policy governing the proliferation of outdoor lighting in the Valley. There have been no limits set on the amount of lighting nor is there any official policy on how much and what kind of lighting is desirable and where it should be installed.

As a result of this neglect, the night is being edged out by artificial, incandescent twilight. Some might argue that the prevention of crime and protection of public safety are reasons enough to erase the night. It’s not at all certain, however, that streetlights affect crime rates. As for public safety, flashlights would seem a more appropriate answer in the National Parks.

The issue here is one of values. Do we prize the convenience of brightly lit streets and walks more than the esthetic pleasure of a truly dark night? Is expedience more important than wildness in a national park?

We direct only the smallest fraction of our interpretive energies towards introducing visitors to the Park’s night-time environment. While flying squirrels, ringtails, raccoons, bats, shrews, porcupines and other nocturnal creatures are abroad, we find ourselves interpreting the park in auditoriums and amphitheatres, showing slides and movies of the daytime scene. While stars and galaxies wheel overhead, we find ourselves gathered around campfires, singing and talking of the daytime world, ignoring the visible universe as if it were not a part of our reality.

Some claim that this entire argument is alarmist. After all, they point out, Yosemite Valley has a much darker, starfilled night than New York or Los Angeles. While that is true, it misses the point.

On the “night prowls” and “star walks” this writer has conducted, the usual first impression of park visitors (once they overcome fear of the dark) is the joy of being abroad at night. A common second impression is frustration as the realization comes that complete escape from the blinding glare of street lamps and headlights is not possible even in Yosemite. One’s eyes must constantly adjust and readjust to the changing light levels. None of the valley meadows is completely free from this annoyance. None is truly dark.

What can be done to resotre the night? The elimination of streetlights and architectural and decorative lights would be a commendable first step. Reduction of all outdoor illumination to a minimum level seems a reasonable goal. Perhaps all outdoor lights could be extinguished after some specific hour, 11 p.m. for example.

The opportunity in Yosemite Valley for urban visitors to rediscover the values of the night has not been sufficiently explored. The impact of outdoor lighting has not been fully appreciated. “ . . . The gifts of the night,” continues Lopez, “while more obscure, more abstract than those of the daylight hours, are no less valuable. The night is as important to the human psyche as is pure water to the body.”

A dark-haired little girl of nine years tugs at my sleeve. We’re standing, she and I and a group of thirty adults and children, in a dark meadow watching the light from thousands of stars. I’m talking about the structure of the Milky Way Galaxy — the swarm of 100 billion suns which constitutes our local universe. We’re standing beneath this unforgettable dark sky and she tugs at my sleeve.

“How far away are the stars?” she asks.

“So far away that their light takes thousands, in some cases, millions of years to reach here,” is my response.

“Where did they come from?” she persists.

“From great clouds of hydrogen gas in space,” I answer.

She’s marvelling at the sky. We are all marvelling at the awesome immensity of the universe. She continues to grasp my sleeve; she’s onto something. Everyone listens intently. These questions are their questions also.

“Where did the clouds come from, where did the hydrogen come from, where did everything come from to begin with?” she asks the ultimate question.

“We don’t know,” my feeble reply, “Maybe it was always there.”

My answer doesn’t surprise anyone. Most of us have stopped asking questions like these. Perhaps we’ve become cynical about that kind of quest. The great mystery of the universe, the mystery of our own lives is one we’ve ceased to ponder. Clear, dark skies beckon one to reflection, however. Like meditation on some dark, mysterious mantra, a few hours beneath the stars can be a mystical experience. A time when we can know as Albert Einstein said “That what is impenetrable to us really exists, manifesting itself as the highest wisdom and the most radiant beauty . . . this knowledge, this feeling is at the center of true religiousness.”



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