From almost anywhere on the Las Vegas Strip you can look west and see it: a pale ridge on the skyline that carries snow into June, rising almost twelve thousand feet above a valley that bakes at a hundred and ten. It looks like scenery. It is closer to an island. The Spring Mountains stand marooned in the middle of the Mojave, cut off by desert on every side, and like a true island in an ocean they have grown a world of their own — cool, green, and full of creatures that live here and nowhere else on the planet.
An island in the desert
An island does not need water around it, only a barrier its life cannot cross. For a cool, wet mountain forest, a hundred miles of blistering desert is as good as a hundred miles of sea. Nevada is an archipelago of them, range after range rising cool out of the sagebrush sea — but few stand as high, or as alone, as this one. The Spring Mountains cover some eight hundred and sixty square miles and rise nearly two vertical miles from base to summit, with the nearest ranges of comparable height more than a hundred and thirty miles away across the sand. That isolation stacks the mountain into bands of life, each keyed to elevation: creosote and bursage on the desert floor, then blackbrush, then pinyon and juniper, then ponderosa, then white fir and aspen, and finally limber and bristlecone pine bent low near the top, with a scrap of true alpine tundra above the trees. A Forest Service ecologist once put it that climbing from the bottom of Kyle Canyon to the summit of Mount Charleston takes you through as many life zones as a drive from Mexico to Alaska. The pale rock those forests grow on is old sea floor, hauled two miles into the sky — a story told in The Sea Over the Sand. The life riding on top of it is the island's own.
Found nowhere else
Isolation is an engine of newness. Marooned for tens of thousands of years, the mountain's plants and animals drifted away from their lowland and Great Basin relatives until they had become something distinct — by the Forest Service's estimate, some twenty-eight kinds of plant, animal, and insect that occur in these mountains and nowhere else on earth. Palmer's chipmunk works the high forest between about seven and ten thousand feet, a species the whole world keeps in this one range. The Spring Mountains springsnail lives out its life in a handful of spring pools that a dry decade could erase. At least seven butterflies are endemic, several of them bound to endemic wildflowers they alone pollinate. It is island evolution in miniature, a Galápagos of cool air set down in the hottest desert in North America — and, like most island life, it is easy to lose and impossible to replace.
The blue on the ridge
The emblem of all of it is a butterfly you could hide under a fingernail. The Mount Charleston blue lives only on a few wind-scoured ridgelines above eight thousand feet, flies for about two weeks at the height of summer, and lays its eggs on two mountain wildflowers and nothing else. It went onto the endangered species list in 2013 — a month after the Carpenter 1 Fire, the largest wildfire ever recorded in the range, burned close to twenty-eight thousand acres through its country. The fire looked like an ending, and it was not quite one. A century of fire suppression had let the forest crowd in and shade out the sunny meadows the butterfly needs, and the burn pried them back open; the host and nectar plants returned, and the blues drifted back onto the scorched ground. The deeper threat is slower and has no firebreak. As the climate warms, the cool bands each endemic depends on creep upslope — and on an island, there is only so much up. Above the summit there is nowhere higher to go.
The living mountain
Long before it was a recreation area, the mountain carried another name and another meaning. To the Nuwuvi — the Southern Paiute — the Spring Mountains are Nuvagantu, and they are not a backdrop but a beginning: in the Nuwuvi creation account this is where the people were made, the origin ground of a homeland that once reached across four states. The land here is understood to be alive — to have, in the words the Nuwuvi Working Group offers at the mountain's gateway, eyes to see you and ears to hear you — and charged with puha, the power that moves through living things. It is not language a wildlife biologist would use, but it points at the same fact the endemics do: this is a living place, singular and easily broken. Since 2008 the Nuwuvi have co-stewarded the range alongside the Forest Service, tending a mountain their people have cared for since the beginning. The other side of Nuvagantu — its snowmelt feeding the springs that raised Las Vegas — is The Meadows and the River. This story is about the mountain itself, still alive at the top.
What the island holds
Drive up out of the valley and in a single hour you climb from creosote flats near a thousand feet to bristlecone pines twisting out of the limestone near twelve thousand — every life zone between the Mojave and the Canadian Rockies, folded onto the side of one mountain. Kyle Canyon and Lee Canyon carry trails up through the fir and aspen to that gnarled timberline; the springsnails hold their pools; Palmer's chipmunk works the pines; and on the high ridges each summer the blue butterfly flies its two brief weeks. All of it is kept alive by nothing more than height — the cool island the desert cannot cross, and cannot help but slowly warm. From the Strip it reads as a pale ridge on the western sky, easy to drive past on the way to somewhere louder. It is in fact one of the rarest things in Nevada: an island a hundred miles from any shore, with a whole living world stranded on its summit.