High, Wild, and Lonesome

A rite of spring brought these nine Abert Squirrels together for a one-of-akind family portrait. Aberts are residents of upland ponderosa forests of Arizona. A cousin under the skin is the rare Kaibab squirrel, inset. Though probably descended from common stock, this latter fellow is only found on the Kaibab Plateau, isolated from southern neighbors by the Grand Canyon. James Tallon photo (Inset) Willis Peterson photo Above and beyond the great chasms carved by the Colorado River, northwestern Arizona is a burnished upland so rugged and so remote it has been described as an American Tibet. Its isolation is the legacy of a geologic tug-of-war. The ancestral Colorado River, say earth scientists today, has not always cut a southwesterly course toward the sea. Long ago, the stream may have surged southeast-roughly along the present-day route of the Little Colorado River. The flow filled a large lake known to scholars as Bidahochi, finally spilling into the Gulf of Mexico. Across the uplifted Kaibab Plateau, to the west, another drainage system, the Hualapai, tapped the runoff destined for the Pacific. But turmoil deep within the Earth squeezed the Kaibab Plateau higher and higher. As that happened, the Hualapai gradually gnawed its way eastward until finally, some 10 million years ago, the two systems wedded.

The Hualapai, being lower, captured the waters to the east. The Little Colorado reversed its direction, pulling the plug on Lake Bidahochi. And the new Colorado commenced its inexorable etching, through the 1.7 billion years of rocks in the Grand Canyon. That whim of nature, then, begat the separation from the country to the east and south of what Arizonans refer to as the Arizona Strip. Even now, the Strip is an island of solitude. Almost all its 8000 square miles are either Kaibab National Forest land or grazing ranges administered by the Bureau of Land Management (BLM). Fewer than 3200 people live there, almost all in hamlets hugging the Utah and Nevada borders: Fredonia, Colorado City, and Littlefield. If dispersed, residents could occupy two and a half square miles apiece. (The population density of Arizona, a state scarcely overcrowded, is less than 16 persons per square mile.) Last winter, three of us spent a chill, cloudy day four-wheeling the corrugated roads of the extreme western Strip Country. Snow wreathed 8350-foot Mount Bangs as we bumped across the southern flank of the Virgin Mountains and into Lime Kiln Canyon. We drove down Cottonwood Canyon and along the Grand Wash Cliffs that snake south to where the Colorado empties into Lake Mead-and returned past Mud Mountain. All that day, we encountered only four other people. Three of those were the mining company representatives my companions from BLM, George Pat Sheppard and Dan Sokal, had arranged to meet. By Strip standards, that was a sociable day. Most of this rocky, hardscrabble ter-rain is inaccessible save by four-wheel drive vehicles. Much of it can be penetrated only by the most intrepid backpackers.

The Natural World of the Arizona Strip by There are places where one could go weeks without seeing another soul.

Still, it is less the loneliness than the surroundings that make the generally arid Strip so spellbinding. The hills are red and gold, the vistas infinite. The myriad canyons are starkly stoney jumbles. The sense evoked is of a universe not yet finished.

Because of the seclusion and the diversity of habitats from low deserts to coniferclad peaks-and because so much of it is naked rock, the region is a living laboratory of biological adaptation and geological processes, a domain of plants and animals and, surprisingly, of fishes that

Strip Country NATURE

live nowhere else. For one, the pink Grand Canyon rattlesnake has, over millions of years, taken on the protective coloration of its setting. It is found only in the Canyon depths, on both sides of the river.

Yet, there are small mammals, believed by biologists to have come from common ancestors, that have evolved on opposite rims of the Canyon in slight but discernibly distinct ways. The long-tailed meadow mouse, the bushy-tailed wood rat, and the long-tailed pocket mouse of the Strip Country's North Rim differ from the Mexican meadow mouse, the Mexican wood rat, and the rock pocket mouse on the South Rim. None of these divergencies has been more striking than those among the Abert and tassel-eared Kaibab squirrels. Scientists are convinced the two colorful rodents are descended from the same stock-and probably were identical until they became divided as the canyon was excavated. Each species is large as squirrels go. They weigh almost two pounds and measure about 20 inches in length. In general, they are of the same hue: a dark iron-gray. Their backs are streaked with a maroon stripe. But the tail of the Abert squirrel, a fairly widespread resident of the Arizona mountains, is gray. Its belly is white. And its Kaibab cousin, stranded on the plateau across the river, has a black belly and a showy, snow-white tail.

No one knows why the difference in markings. It may have something to do with camouflage, like the pink of the Canyon rattler. That explanation does not bear up. The North Rim is higher than the South Rim and therefore more prone to winter storms. Thus, the Kaibab squirrel's white tail might afford some protection against predators. Its dark body, though, makes the animal notably conspicuous as it darts over the snow.

Strip Country NATURE

Why do the two never meet? Each feeds almost exclusively on piñon pines, primarily the twig ends. There are no piñons in the arid canyon bottom. Nor are there any in the lower dry reaches hemming in the forested Kaibab Plateau in every direction. This reality restricts the Kaibab squirrel, one of the rarest of American animals, to a range of no more than 350 square miles. To the northeast, in House Rock Valley, at the Strip's eastern edge, there survives a plant even more unusual, a tiny pincushion cactus so uncommon it has no common name. Indeed, botanists suspect only a scattering of the cacti, Pediocactus bradyi, persists on a few lonely limestone ridges.

This northeastern slice of the Strip, since one of the region's few ribbons of pavement bisects it, is all most travelers ever see. While they miss the Pakoon Basin and the other badlands far to the southwest, they nonetheless drive through a dramatic introduction to a Tibetan landscape. Until Navajo Bridge spanned the Colorado, just south of Lees Ferry, in 1929, no road tied the Strip to anywhere else in Arizona. Highway 89A now heads from the bridge west across House Rock Valley.

Thinly carpeted with Indian ricegrass and spiney shad scale, the valley slants southward toward the river, the openness relieved only by a lacework of steep-sided arroyos or washes, that widen as they near the Canyon.

Dominating the scene to the north, however, the kaleidoscopic Vermilion Cliffs soar up 2500 feet above the highway. The cliffs exhibit a geologic history dating back 230 million years; an epic of the rise and ebb of seas, the march and retreat of desert dunes, the life and times of creatures long vanished.

Not unlike the walls of the Grand Canyon, the cliffs are banded by age, with the oldest rocks at the lowest level, the latest on top. But all these, the geologists say, are younger rocks than those within the Canyon. That is, they were laid down more recently. Their warmth contrasts with the dun color of the valley below.

Capping the cliffs-and hence the most recently concreted of the cake-like layers-are 1200 feet of reddish-brown buttes, peaks, and precipices of Navajo sandstone. They formed from wind-blown dune sands when this was a desert as vast as the Ar-Rab Al-Khali (Empty Quarter) of Saudi Arabia.

Below that are the lighter red-brown mudstones and siltstones, which are finer than sandstone, of the Kayenta Formation. These were left behind by streams when dinosaurs still stalked the Earth.

The Triassic-age Moenave Formation is pale brown. Then come the blues, grays, and greens of soft Chinle shale, molded into smooth round slopes beneath tropi-cal swamps. The Chinle is the palette of the Painted Desert farther to the east, and it was in the warm bogs of its birth that wood began to petrify.

Bottommost of the strata is the shale and sandstone Moenkopi Formation, light to chocolate brown. From the shells and fossil fishes encrusted there, it is known the Moenkopi was at least partly the relic of a receding ocean. The cliffs run east to west the full length of House Rock Valley. As the valley floor slowly rises in elevation to cooler, more moist heights, the vegetation becomes mainly sagebrush and dark-colored blackbrush.

Antelope play beside the foot of the piney Kaibab Plateau. And Highway 89A, wending west, surmounts the gentle slope of the plateau before ascending through rolling red prairies to Fredonia.

Strip Country NATURE

South from Fredonia, most of the Strip sprawls out over a generally roadless wild land of labyrinthine canyons, peaks, and plains. Even some of the place-names hint of challenge and deprivation: Starvation Point and Poverty Spring and Hells Hole. These are the haunts of desert bighorn sheep, of eagles, and of endangered peregrine falcons.

From the lofty flight paths of those great birds of prey, one of the Strip's high points, 8029-foot Mount Trumbull can be seen lording over the Grand Canyon. In 1877, Trumbull supplied ponderosa pine rafters that still support the Mormon temple at St. George, Utah, 72 miles away.

Once, during a period of vulcanism, Mount Trumbull and its neighboring cones spewed out enough molten debris to dam the Colorado River. Lava Falls, the remnant of that fiery era, is held by river boatmen to be one of the more tempera-mental American rapids.

From the same eagle's-eye view, it can be seen that the western Strip is not the gentle rise of the eastern Kaibab but, rather, two gigantic steps downward.

First the Hurricane Cliffs and then, to the west, the limestone Grand Wash Cliffs, awesome evidences of the Earth's faulting, plummet 1000 or so sheer feet. The Colorado Plateau, which can be visualized as a series of saucers stacked one against the other and all tilting eastward past the Four Corners Country, ends abruptly at the Grand Wash Cliffs.

Below is the basin-and-range province of low desert broken by mountain ranges that, like the Virgins, generally trend north to south. The creosote-bush Sonoran Desert, the Joshua-tree Mojave, and the shad scale and sage Great Basin meet and meld in this end of the Strip.

There, too, the area's busiest highway slashes for 29 miles across extreme north-western Arizona, threading together Las Vegas and the cities of Utah. For 11 of those miles, Interstate 15 is suspended like a spider web through the Virgin River Gorge, 150 feet wide, with vertical rock walls that rise 500 feet.

Few motorists could know they literally are driving above two of the world's most distinct populations of tiny minnows. Woundfin minnows and Virgin River roundtail chubs once swam much of the Lower Colorado River basin, as far east as Phoenix. Their world now has been confined to the Virgin, one of the few Southwestern streams not overly dammed and diverted. Both are believed to be on the brink of extinction. They are most numerous near the farming village of Little-field, where the Virgin River and Beaver Dam Wash join between sandy banks of willows, cottonwoods, and salt cedars.

Living farther up the wash is a creature whose existence may be even more precarious. This is the northernmost range of desert tortoises. Left alone, the terrestrial turtles may live as long as a century. They are menaced now by the overgrazing of livestock, off-road vehicles, and collectors. The minnows and the tortoises could be (Left) Where do you go to photograph trophy-size mule deer? The Arizona Strip's Kaibab Plateau, of course. The dimensions of their antlers, biologists say, may be the result of a high percent-age of calcium in the soil. These deer spend their entire lives on or near the plateau, once a favorite Indian hunting ground. To white men of that earlier day, the Kaibab was Buckskin Mountain.

In 1893, the Kaibab, which means mountain lying down, became a national forest.

(Right) A summer's shower embroiders a thousand elfin stars in the galaxy of a spider's web. Inge Martin photos

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the symbols of the region's fragile ecological future, for profound change may yet intrude on this Technicolor outback.

The economic fate of the Strip well may have been sealed some 300 million years ago when an enormous limestone layer was banked in the wake of oceanic intrusions. Actually, the so-called Redwall limestone, rich in the remains of primitive marine organisms, is blue-gray in color. But in the Grand Canyon, where it first was noted, it was given a crimson veneer by iron oxide leaching from the red rocks above. The Redwall is 500 to 600 feet deep there, the thickest of the Canyon's formations. Away from the Canyon, it became smothered over the eons by, among other things, the dust and rock expelled from volcanos.

Time works in wondrous ways. Some of the volcanic cover settled into depressions called breccia pipes that reach down to the Redwall and act as traps for minerals. Uranium of an unusually high grade has been discovered, in the past few years, in a number of the pipes.

The Strip, so long passed by, could become a focus for intensive mining and new populations for the American Tibet.

(Left) The Inner Gorge of the Grand Canyon, from Plateau Point on the South Rim. Author-naturalist Joseph Wood Krutch saw the Canyon as "the most revealing single page of earth's history open on the face of the earth." There, granite, shale, limestone, and sandstone tell a tale 2000 million years old.

(Inset, below) Among steep and craggy canyons of the Arizona Strip Country some desert bighorn sheep can be found, generally in bands of 12 to 15. At maturity, a large ram may weigh 300 pounds. Ed Cooper photo (Inset, below, left) The desert tortoise. A vegetarian, he's at home in the hot, dry sections of the Arizona Strip where he's protected by law. A relative of the giant tortoise of the Galapagos, the desert tortoise reaches 14 inches in length at maturity. James Tallon photos