Perhaps nowhere else in the world have so many people been introduced to the study of geography and anthropology as in Arizona. Here, the Grand Canyon constitutes the finest possible textbook on geology, while the numerous well preserved ruins and relics of prehistoric cultures form a similarly interesting laboratory for the study of earliest human life in the Southwest.

Nor are there many other places in the world where geography -- in all its phases -- comes so dramatically alive. Here the relationship of the land to the people who have inhabited it is fascinatingly apparent; here the effects of the land and climate of human cultural patterns is readily observed by even the untrained; and here the course of human history has been spurred and slowed and spurred again by the earth and climate.

Recent scientific studies have led geologists to estimate the age of the earth as 3,350,000,000 years. The mountains and deserts we see today in Arizona are so huge, so vast, and so serene -- especially on a glorious clear, starry night -- we tend to think of them as eternal. Yet they have been here in approximately there present form for only a minor portion of geologic time. Indeed, the topography of Northern Arizona reached its present conformation only a thousand years ago.

It is fascinating to consider that the land of Arizona with its mineral deposits, its rich soils, its mountains and deserts, its rivers and hot springs and forests and valleys was in preparation for lengths of time that stagger the imagination. Be it three billion three hundred fifty million years or only a billion or two; what's the difference? It still is true that man has existed in Arizona for only the tiniest fraction of time. Geologists and anthropologists are agreed that man is known to have lived here for only about twenty-five thousand years -- something like one ten-thousandth of the time Arizona was in the making.

Yet in the ridiculously short period of a century, man has made tremendous inroads on the treasures it took nature billions of years to store here. Prodigality and wantonly man dug and lasted the precious and semi-precious metals from the ground, grazed huge herds that ate down the grasses, further denuded the land by cutting trees and bushes for firewood and lumber and then stood aghast at the erosion and deterioration his handiwork had caused.

In the last few years, man has profited by his mistakes. Now Arizona is one of the world's leading conservation areas. Man has learned that to survive he must conserve the resources given him by the work of geologic ages. Erosion is being fought to prevent loss of precious top soil. Great dams impound the waters of rivers so man can use them to make the rich valley soils bear crops. The power of these same waters is harnessed to make electricity. The forests are strictly supervised to assure their sustained yield, while the vast ranges are grazed by herds limited to the carrying capacities of the grasses.

Only in the case of metals has men been unable to restore at least partially the depletion of natural resources in Arizona. The state is dotted with exhausted mines from which no more gold, silver, copper, zinc, lead, and other metals can be gleaned profitably. Yet modern metallurgical methods have enabled man to use vast deposits of low-grade ores which a few years ago would not have been worth mining. So vast are these remaining deposits, responsible scientists have said that by the time they are exhausted, man will long since have harnessed atomic power well enough to enable him to extract from the sea the almost unlimited deposits of metals of all sorts now in solution in ocean waters. These same scientists predict also that similar processes will be used to purify sea water and transport it for domestic, agricultural and industrial uses in arid and semi-arid regions hundreds of miles from the sea.

If and when the sea is brought to Arizona it will be, in a sense, a repetition of something that has happened a number of times during geologic ages. During the earliest era recognized by geologists, the Archean or Archeozoic, Arizona apparently was a land of mountains and hills and valleys. Rain and wind beat at the mountains in the constant leveling process of nature, and bits of rock and other detritus were carried into the valleys, filling them readily with alluvial deposits.

Below the surface of the earth, however, great forces were at work, pushing molten rock up finally to burst up and flow into new peaks and contours. The volcanoes produced igneous rock of hard and extremely durable nature. The heat of the volcanic activity distilled below ground gases and vapors containing metals and sulphur. These penetrated fissures in subterranean rocks and formed there copper and other metal deposits, and B. S. Butler (Arizona and Its Heritage; Geology. University of Arizona Bulletin, Vol. VII, No. 3; April, 1936) says it was in this earliest geologic period that the copper and gold deposits of the Jerome and Prescott areas were formed.

The principal difference between the Archean Arizona and Arizona today is that there was no life here then. No trees, no grasses, no animals or plants of any kind. The mute evidence of the division away back then can be seen clearly in the inner gorge of the Grand Canyon. This is one of the best views in the world of Archean rocks in their relationship with subsequent formations.

The second geologic era is called the Algonkian or Proterozoic, and it was during this tremendously long period that Arizona was largely under water for the first time. Igneous rocks of this era are found, as are brilliant red shales that were formed as muds accumulated by huge rivers. These shales still show ripple marks which indicate changing currents. Moulds of crystal salts are found in the shales, indicate taken while large shrinkage cracks indicate they were baked by a very hot sun in an arid climate. This was at least six or seven hundred million years ago.

An interesting aspect of the geological record of the Algonkian period in Arizona is the inclusion of layers of limestone among Algonkian strata at the Grand Canyon. These limestones represent great reefs which were built up in the seas covering that area. The first definite record of life in Arizona is contained in these reefs, for they were built up by the action of primitive unicellular plants, algae.

A few years ago it was noted that a similar limestone structure is being built near Harper's Ferry, Virginia. A study of the ancient limestones in Grand Canyon and the Harper's Ferry limestone convinced scientists the Grand Canyon Algonkian limestone was made by the same process that is still going on in Virginia, by the action of algae. Thus these tiny plants were the first life positively known to exist in this region.

It was during the Algonkian era also that the deposits of long-fiber asbestos were formed in what is now the Globe-Apache Indian Reservation section of the state.

Geologists estimate the first two eras of the earth's history cover by far the largest period of time, perhaps two-thirds or more. The balance is divided into three further eras: the Paleozoic, or ancient; the Mesozoic, or medieval; and the Cenozoic, or modern.

During the Paleozoic era, rock masses protruded of the surface of the seas in Arizona. Winds and rains and the lapping of waters at their bases constantly wore away these peaks, depositing the detritus in the seas as sand, clay or limestone, which were the course of interminable years, became rocks. These deposits spread more most of the northern and southeastern sections of the state, and it was in these Paleozoic sedimentary rocks that, in a later era, volcanic activity deposited more of the metals upon which a large part of recent Arizona economy has been based.

The most significant aspect of the Paleozoic era, however, is that it is known positively to have fostered both plant and animal life. Scientists are not entirely agreed on the question of whether or not there could have been animal life in the seas of the Algonkian era. There is a possibility that soft-bodied animals did exist then, but that when they died, their bodies completely disintegrated, and the we have no proof of their existence.

There is no doubt about the Paleozoic animals' existence, however, because in many sections of Arizona we have beautifully preserved seashells, footprints, impressions of ferns, corals and other forms of life. Indeed, by the end of the Paleozoic era, air-breathing land animals and early land plants had evolved, as had also amphibians, reptiles and seed-bearing plants.

The rocks of this age were formed, as all sedimentary rocks are, by the deposition by wind and water of sediments over vast intervals of time. In them we can read the story of the progress of life forms. While two chapters of the story of this era are missing from the Grand Canyon (which apparently was above water during those periods and thus did not received any deposits), the Grand Canyon shows clearly the Cambrian period which produce the first definite traces of animal life; the Devonian period, known as the age of fish, during which primitive sea creatures depended largely on a sort of bony skin armor for protection; the Mississippian or Lower Carboniferous, during which a wide and quiet sea stretching over most of the area from Arizona to western Canada laid down deposits of unusually pure lime in which are found a vast accumulation of beautifully preserved skeletons of intent plants and animals; and finally the Pennsylvanian period of vast swamp forests, the evolution of insects, and, in some parts of the country, the formation of coal beds of which Arizona has a few.

The two periods not recorded in the Grand Canyon are the Ordovician and the Silurian which follow the Cambrian in that order. It was during the Ordovician that the earliest vertebrates developed, including sharks. Sharks' teeth have been found fossilized in rocks of the Oak Creek area. The Silurian gave rise to the first air-breathing animals, scorpions, which still inhabit the warmer sections of Arizona in large numbers. The Paleozoic age and with the Permian period, during which there was a great climate readjustment that killed off many forms of Paleozoic life.

The next great geologic era, the Mesozoic, produced a condition that modern Arizonans find hard to believe. Southwestern Arizona, which is now the lowest part of the state in altitude, was a Mesozoic highland, of water probably throughout the entire era. On the other hand, Northern Arizona, now mostly a high plateau, was a Mesozoic lowland and at times a shallow sea.

This was the age of reptiles, during which the great dinosaurs held sway in the animal kingdom. They left their footprints in many parts of Arizona and apparently enjoyed a long and healthy reign here. However, by the end of the era, they had become extinct. Their place of ascendancy was taken by archaic mammals and small marsupials, while the plant world was evolving modern trees and flowering plants.

It was during the Mesozoic age that in many parts of the world, vast quantities of animal and plant life were buried in seas of mud and sand to be turned into coal, oil or gas. In Arizona there were plants that might have been turned into coal. But nature worked another wonder instead. The water into which some of Arizona trees fell was so constituted chemically that it soaked into the trees' cells and replaced them with silica, then producing the world-famous petrified forests of the Northern Arizona plateau country. Just east of Holbrook today is the Petrified Forest National Monument, which preserves the most striking concentration of petrified logs; however, the forest itself extends from east of Holbrook northwestward to the Colorado River.

During the middle of the Mesozoic era vast forces deep within the earth began to raise a strip of land west and north of Arizona slowly but inexorably out of the sea and far above it. Great blocks of the earth's crust were broken and folded and tilted to become mountains, the ranges we now know as the Sierra Nevadas and the California Coast Range.

At the end of the Mesozoic era and early in the succeeding era, the Cenozoic, a similar upheaval took place, raising the great Colorado Plateau and creating the Rocky Mountains. When this was accomplished, and the present climate of Arizona became inevitable, for the Rockies and Sierra Nevadas largely are responsible for the directions of the winds in Arizona, for emptying most clouds of their water before they are blown over Arizona, for blocking or funneling air masses and weather fronts, and in general, constituting major factors in the determination of Arizona climate. Of course, many other facts also contribute; but have not the Mesozoic and Cenozoic eras produced the two great ranges, these other factors would have been considerably changed.

The Oligocene produced many higher mammals, such as the giant pig, rodents, dogs, and anthropoid apes. Many of these types existed in Arizona, although it is not established that Arizona had any population of apes.

The Miocene period saw the rise of mastodons, camels, horses, cats, deer and so on, and Arizona had its full share of all these species. Indeed, only the mastodons and camels are gone now, although the latter were brought back experimentally in the 1800s from the Mediterranean. During the Miocene period, more petroleum and natural gas deposits were made in many parts of the world, and it is not improbable that in Arizona provision oil and gas fields will still be found despite early disappointments.

The Pliocene period was the first to produce manlike types of mammals. Pithecanthropus erectus has been dated from about 750,000 B.C. No evidence of this creature's presence in Arizona has been found to date. Indeed, throughout the final phase of the Cenozoic era, the Pleistocene period, we find no evidence of man or his predecessor manlike creatures in this area. The Pleistocene was the ice age, during which the last continental ice sheets formed, culminated and receded. While they did not reach so far south as Arizona, actually they affected the climate considerably, and during the time they were receding and melting, they brought abundant rain to Arizona to make its fertile valleys yield rich grasses for support of animal life and to supply the soil with humus.

Much of the Cenozoic era and a very considerable portion of its successor, the current geologic age, witnessed great volcanic activity in Arizona. At the end of the Mesozoic era there were great eruptions of molten rock in northern Arizona along the southern edge of the slowly rising plateau. Hundreds of square miles were buried in blazing lava, which, cooled and hardened, still remains there today.

This same activity continued throughout the Cenozoic era, the molten rock sometimes bursting through the earth's surface to form mounds, sometimes remaining locked under sheets of rock. When this latter happened, the subterranean lakes of molten rock produced gases and vapors which penetrated fissures in the rocks and formed there more deposits of copper and other metals.

Volcanic activity continued intermittently throughout the Cenozoic era up until very recent times. As a matter of fact, it might be said still too the represented in the state by the numerous hot springs found in the various areas such as the Verde Valley, the Safford area and the Salt River Valley.

It was through this volcanic activity that Arizona was blessed not only with abundant metal deposits but also some of the finest mountains, most notably the San Francisco Peaks. E. D. Wilson (ibid, Physiography, p. 22) states the San Francisco Peaks originally rose approximately 3,000 feet above their present summit of 12,670 feet, the highest point in the state.

It is interesting to note the constant, inexorable leveling process of nature. Peaks are raised only to be attacked by erosion of wind and water, and by the cracking and crumbling processes of sun and freezing cold. Sometimes the results are graceful, flowing lines, as in the case of the remaining San Francisco Peaks. In other cases the results are quite startling. A volcano would pour out ashes and lava, sometimes more ashes than lava, thus making the mound at its base porous and rather easily susceptible to erosion.

Yet the core of the volcano would be of purer lava, or molten rock, and this would cool more slowly and harder. As the winds and rains of ages beat against the peak, all but the core would be eroded away, leaving a jagged, bare rock plug towering above the surrounding country. Northern Arizona is dotted with these volcanic necks, some of which rise as much as a thousand feet or more above the land at the base.

Of course the most particular example of the result of erosion in the world is the Grand Canyon of Arizona. When the Colorado Plateau began to rise, starting at the clothes of Mesozoic times and continued during Cenozoic Times, the sometimes abundant rains that fell on it sought and found a watercourse to the sea. As the Rocky Mountains reared higher and higher, the water from their western slopes ran more swiftly into the plains below, carrying with it its of rock and sand and sometimes even large stones and boulders. These were dragged and rolled along the bed of the ever-growing stream, which used them as gouges to tear at the rocks over which it flowed. It was a case of water grabbing every means at hand the more efficiently to fulfill nature's law that water must seek its own level.

When a core of harder than average rock was encountered, the river took the easier course, split into two branches and flowed around the obstruction; but it was not a surrender. Slowly, relentlessly, the two branches would dig their channels deeper on either side of the obstruction, isolate it, then undercut it, finally topple it, break it into small bits and then use it to attack other obstacles further downstream. In this manner the Grand Canyon was dug even wider and deeper until today it is at places more than 12 miles wide and a mile deep, with a total length from near the Utah order to the Grand Wash Cliffs of some two hundred eighty miles.

Startling as these dimensions are, however, it is still more startling to learn the floor of the Grand Canyon now actually is more than two miles below the highest level once attained by the surrounding land. Wilson (ibid) says, "During and subsequent to the uplift of this region [the Colorado Plateau] in Cenozoic time a thickness of more than 6,000 feet of strata was stripped from the plateau. At the same time the Colorado River, cutting downward much faster than the general surface of the plateau could be planed away by erosion, excavated hundreds of cubic miles of solid rock."

The phrasing in this statement is very fortunate. Note the river's action is cutting; the general surface of the plateau is planed. The river gathers its tools and uses them well. The plain, however, is subject to a combination of forces. Extreme heat dries, cracks and peels mud, readying it for the action of the wind. Cold condenses moisture in cracks and fissures of rocks, freezes, and expands it, enlarging the cracks and making them more susceptible to the eroding action of water and wind-blown sand and dust. Wind and water gather the detritus readied by weathering, grind it even smaller and carry it finally to the river and thence to the sea.

Modern man for many years forgot or ignored the relentlessness of this process. Only after formerly fertile plains were turned into dust bowls and formerly productive ranges had become barren slopes did he realize the error of his ways. He has hastened to spend fortunes to return a layer of nature's own insulation, vegetation, to the soil to conserve that most precious of all resources.

The topography of Arizona as we know it today did not really take shape until only about a thousand years ago with the last important volcanic eruptions. Perhaps the most recent major landmark left by this action is Sunset Crater, a peak about fifteen miles east of Flagstaff. It derives its name from a rim of reddish cinders near its top which gives it the appearance of being perpetually lighted by a sunset glow.

However, the major features of Arizona's topography were established many years before that during late Mesozoic and the course of Cenozoic times. The Colorado Plateau was raised to make the present high plateau which constitutes the northeastern third of the state. A combination of volcanic action and the rising, cracking, and folding of the earth's surface produced the central third of the state, the mountain area running diagonally from northwest to southeast. And finally, a settling of the land in relation to the other two regions left the southwestern third a low desert in which local cracking, folding and upheavals of the earth's crust produced low, rugged and mostly barren mountain ridges which rise dramatically above the desert around them.

These three -- the high plateau, the mountain and desert -- then are the main geographical regions of the present state of Arizona. Within the plateau are two principal areas which most clearly show evidence of recent volcanic activity, the area around Flagstaff and the San Francisco Peaks; and that around Baldy Peak, near Greer and Alpine in the White Mountain country.

The surface of the plateau ranges from about 4,300 feet altitude to more than 9,000 feet above sea level, a difference accounted for mainly by the bulges and folds and faults in the bed rock caused when the whole area was being forced upward. The plateau is carved with a number of sheer canyons -- most notably the Grand Canyon of the Colorado and the canyon of the Little Colorado. There are, however, other dramatically beautiful canyons such as Havasu Canyon, part of the Grand Canyon complex; Oak Creek and Sycamore Creek canyons, which slice into the southwestern face of the plateau known as the Mogollon Rim; and Canyon de Chelly, on Chinle Creek in the northeastern corner of the state.

The plateau is also marked by other natural wonders. Between Flagstaff and Winslow is a tremendous hole in the ground surrounded by a raised lip. This bowl-shaped depression measures about 4,000 feet in diameter, is nearly 600 feet deep, and the ridge surrounding it rises from about 120 to 160 feet above the level of the plateau. Meteor Crater, as it is known, was for some years the subject of considerable scientific dispute. One faction claimed it was caused by the explosion of a huge bubble of volcanic steam; the other said it was made by the impact of either a single giant meteorite or a large group of smaller meteorites. This latter view has been quite thoroughly substantiated and now is accepted as fact.

The surface of the plateau varies from barren, wind-swept wastelands to vast grassy plains to thickly wooded pine forests. One of the world's largest nearly pure stands of Ponderosa pine is that which extends in a great crescent down from the Utah border, along the southern end of the Arizona plateau and across into New Mexico. It spills from the plateau onto the neighboring mountain ranges and provides Arizona -- much to the amazement of many a newcomer who had thought of the state as only a cactus-studded desert -- with some of the country's most beautiful evergreen forest scenery.

The mountain region is composed of forest-covered slopes, some brush-covered mountains and some bare. The valleys created are for the most part fertile, with good accumulations of alluvial soils. Wherever water is available, the valleys generally are sparkling green oases stretched out between the brown foothills.

By contrast, only a very few of the mountains in the southwestern third of the state support any considerable amount of vegetation. This is due largely to the fact they don't reach high enough to contract any appreciable precipitation, as do the central mountains. Thus the contours of the southwestern desert mountains are much more sharply angular and jagged than the central. All of the softer matter has been eroded away, leaving great slabs of bare rock upended drunkenly against the skyline just as they were left by a violent spasm of the earth's surface a few million years ago.

There is, however, a constant change in the height of the mountains, both absolute and also in relation to the surrounding plains. Constantly the mountain is being chopped and gnawed at by the forces of nature; and constantly the valley troughs below are being filled deeper and deeper with the detritus. In many places in southwestern Arizona the alluvial deposits have been measured as more than two thousand feet deep.

The two highest elevations in Arizona are found in the plateau country at the San Francisco Peaks. Humphrey's Peak is 12,670 feet above sea bubble, while neighboring Agassiz Peak is close behind at 12,340 feet. Baldy Peak in the White Mountains reaches an altitude of 11,590 feet, while Escudilla Mountain, west of Baldy on the Arizona-New Mexico border, reaches an exact 11,000-foot altitude. Mount Graham, 10,720 feet high, southwest of Safford, is the state's largest mountain in regard to bulk and reaches further than any other above adjacent valleys and plains, lifting some 7,000 feet above the lowlands at its base. At least two other peaks in Arizona top ten thousand feet, Kendrick in the San Francisco group and Green in the White Mountains. There are many which are more than nine thousand feet high, while heights of seven and eight thousand are almost commonplace.

By contrast, the state's lowest elevation is one hundred thirty-seven feet above sea level near Yuma, making a difference of 12,533 feet between the highest and lowest points in the state. It can be readily appreciated, therefor, that in Arizona altitudes alone will give rise to a great variety of climate. This altitude differential is supplemented by a range of latitude of some 400 miles between the Utah and Mexico borders, which also is sufficient to account for a considerable range of climate.

It is all arid or semi-arid climate, for maximum rainfall in the state is only 32.42 inches per year at Crown King, one of the wettest points at which U.S. Weather Bureau records were kept for a representative period. Driest parts of the state, represented by Yuma, average only about 3.10 inches per year. The wettest areas occur, naturally, at the higher elevations, the driest at the lowest.

Probably the most dramatic expression of the climate range of Arizona is the fact that from the top of the San Francisco Peaks to the floor of the Verde Valley, an airline distance of not more than forty miles, there is represented every possible climate life some of the world except the wet tropical. Above the timber line on the peaks, the climate is Arctic-Alpine, with an extremely short growing season supporting only mosses and similar plants. Just below that is the Hudsonian, in which Englemann spruce and foxtail pine flourish. Then comes the Canadian zone, with its Douglas fir, aspen and white fir. This is followed in the descending altitude scale by the Transitional zone in which the Ponderosa (yellow) pine thrives. Below this is the Upper Sornoran zone, supporting pinon and juniper trees. And finally, on the valley floor, the climate is Lower Sornoran, with its cactus and mesquite vegetation.

Maximum temperatures in the dry desert areas often exceed those at the equator, while minimum temperatures in the mountains frequently are the lowest recorded on a given day in the United States. The little town of Maverick in the White Mountains on the Fort Apache Indian Reservation not infrequently during the winter months important minus 20 to minus 30 degrees, and often during the summer it is the nation's coolest spot.

The effects of these extremes of temperature are mitigated considerably by the lack of humidity. To say that the heat or cold in Arizona does not bother people nearly so much as in other sections of the world is today considered trite; but it is trite only because it's truth has prompted people to say it more often. Heat prostration is virtually unknown, while it is not unusual to find people in the colder cities like Flagstaff walking around in suit coats or light jackets at noontime on cold winter days. H. V. Smith states, "A comparison of the mean annual temperatures of several Arizona weather observing stations with those of others in the United States and in certain foreign stations reveals that Mohawk, Arizona, as a similar mean temperature to Miami, Florida, and Rio de Janeiro; Tucson is comparable with Mobile, Alabama, and Lima, Peru; Flagstaff's mean temperature is not unlike that in Minneapolis, Minnesota or Toronto, Canada. [One of] Arizona's coldest station[s], Bright Angel Ranger Station, has mean temperatures which rival those at Glacier Park or Leningrad, Russia."

Smith also makes the interesting observation that the mean maximum temperatures at Flagstaff Corson almost exactly with the mean minimum temperatures at Yuma.

While there have been extreme changes in the climate of Arizona during the course of geologic time, there has been relatively little during the last several centuries. This fact has been established largely through the quite new science of dendrochronology, "the determination of dates of events and intervals of time in former periods by comparative study of the sequence of rings of growth in trees and aged would." (Webster's New International Dictionary, Second Edition) Developed principally by Dr. A. D. Douglass of the University of Arizona, dendrochronology has succeeded in compiling an almost complete and amazingly accurate graph of the weather of Arizona and other places back nearly 2000 years. It has shown that Arizona in the 13th century and before was a land of drought and tension over water just as it is today.

All of Arizona lies within the the drainage system of the Colorado River. Eventually every stream in the state connects via other streams to the Colorado which forms the major portion of Arizona's western boundary. The principal tributaries to the Colorado are the Little Colorado, the Gila and the Bill Williams. The Little Colorado drains the plateau region, the Gila drains the mountain and desert area, while the Bill Williams drains the mountain and to desert area of the west central section.

The Gila, which arises in New Mexico and empties into the Colorado at Yuma, has as its main tributaries the Salt, San Pedro, Santa Cruz, Hassayampa and Agua Fria. The Salt in turn is fed by the Verde, the Black, the White and by Cherry Creek and Tonto Creek. The Verde receives a large portion of its waters from Oak Creek, Chino Creek and Sycamore Creek.

Anyone familiar with Arizona history will recognize most of those names as figuring prominently in the settlement and development of Arizona. Most human history is written largely around man's need for and use of water; but nowhere is the course of history more directly and obviously influenced by rivers, creeks, springs and rains than here. Where there was water, there man could live and build and prosper; where there was no water supply, man either developed one or he foreswore trying to make the land give up whatever riches it might hold.

A glance at the map of Arizona will show that its vast area of 113,956 square miles (fifth largest among the forty-eight states) has tremendous stretches in which there is no settlement. By and large, the population of of the state is concentrated in the area of the northeastern edge of the desert and the southwestern edge of the plateau, with some concentrations in the mountains. But the northeastern corner and the southwestern corner, being the most arid, are the sections with fewest settlements and the greatest stretches of open country. Only Yuma and its neighboring small towns occupy the huge southwestern section, and they are there today mainly because the Colorado River has been harnessed for their use.

The distribution of towns has been generally governed by availability of water supplies. Of course, other factors have been involved; but it's remains a fact that the majority of the four hundred seventy-seven (in 1958) cities, towns and villages listed on the state's official road-map have sprung up in those areas where drainage from the mountains has created underground reservoirs which can be tapped by wells, usually on or near the bed of one of Arizona's famous dry rivers.

These dry rivers have been the objects of many jokes; but they have been extremely important to the formation of the land, the development of that land and the use to which man has been able to put the land. It was the rivers -- unusually wide, rather slow rivers -- that spread the erosional debris in the valleys. It was they that, having piled rock and sand and soil deep across the valley floors, then carried water to those valleys from the rains and melting snows of the mountains. Not much of this water did they deliver above ground, but rather they dropped it through sandy bottoms to build up reservoirs down on bed rock and covered by sand and soil to prevent its being evaporated.

While newcomers to the state laugh to see signs proclaiming a wide ribbon of sand a river, the chances are good that only a few feet down in the sand, water actually is running, trickling through gravel on its way to an underground reservoir. And it's the river that has the right to laugh at the dude, for the river has been smart enough to protect its precious burden so far as possible from loss by evaporation.

It is, the wide variety of altitude and the resulting diversity of climate that has determined the flora and fauna on the state. The impression entertained by many strangers seems to be that Arizona has only cactus, creosote bush and date palms for flora, cowponies, cattle, rattlers and Gila monsters for fauna. Actually the range of vegetation and animal life is as great as that of the climate life zones.

Briefly, in connection with the life zones, the representative vegetation of each has been mentioned already. In addition to Englemann spruce and foxtail pine in the Hudsonian zone, there is the interesting cork-bark fir among the trees, while the high mountain meadows support luxuriant stands of grasses and herbaceous vegetation. Wild flowers bloom in profusion during the short growing season, while even in the snow, the plucky snowbank primrose blooms.

In the Douglas fir and Ponderosa pine forests, the forest floor usually is clear of underbrush. Sparse grass is to be found, while in the Ponderosa forests' altitudes, one frequently finds beautiful stands of brilliant blue lupines. Occasionally there are small thickets of scrub oak, sometimes called deer brush. At this altitude, too, are found the snowberry and fernbush.

In the next lower zone, the upper Sonoran, the pi–on and juniper frequently are interspaced with a variety of shrubs such as turbinella oak, barberry, manzanita and so on. The junipers are of several types--Utah juniper, one-seeded juniper and the handsome alligator juniper. Another extremely interesting and unusual tree is the Arizona cypress and found in lovely stands in various under the Mogollon Rim at altitudes of about 4500-5500 feet.

In chaparral or brushland areas one finds the shrubs mentioned above plus thickets of Simondsia, an especially attractive plant with a variety of foliage and flower; buckwheats, penstamen, Ceanothus and Rhus. Different cacti add variety and interested. Usually the chaparral brush is evergreen, although occasionally the oaks are deciduous.

Important grasses native to the state are the blue grama (Bouteloua gracilis) of the high plains, one of best of pasture grasses and of high forage value in the state. Another good grazing grass is galleta, which forms an open sod and occurs sometimes in large, practically pure stands.

Widely distributed over the state are the mesquite grasses. These cover larger areas than the blue grama and galleta, although they are found principally in the southern part of the state. They include Tobosa grass, curly mesquite, crowfoot grama and black grama. They start to grow almost immediately following summer or winter rains, and it is not unknown for a crop of hay to be cut from a good stand in a favorable season. However, this is rather rare today, as the grasses have been too closely grazed to encourage such vigorous growth.

Curly mesquite (Hilaria belangerii) in the southern foothills grows in a savanna of Emory oak. After a good rainy season its makes a wonderfully gracious looking range. The Tobosa grass (Hilaria mutica) is especially useful as cover for heavy impervious soils on the surface of which water tends to accumulate after rains. Tobosa is good forage mainly only when green.

Native flora of the desert regions is amazingly varied. North of the Grand Canyon, the desert is covered with large stands of sagebrush. Usually the sage is in nearly pure stands, the bushes from three to six or more feet apart and from two to six feet high. On the ground is very sparse cover, even the sage demands good, alkali-free, open soil. The leaves drop off at the approach of drought and cold weather, growth being confined to spring and early summer. Sagebrush is found in less stands in other scattered portions of the northern part of the state.

Another bush found in a number of pure stands in the area of the Grand Canyon and east of the Colorado to west of the Vermilion Cliffs, is coleogyne. It, too, occupies alkali-free land, and produces dark colored bushes, grows evenly spaced, and is seldom over two feet high.

Alkali land sometimes, although only occasionally in Arizona, grows shad scale. Where its is found, its is on heavily alkaline soil of the northwest. Its low plants are silvery, turn purple in the fall, and lose their leaves completely in winter.

In the southern desert these bushes are replaced by creosote bush. Almost as famed in song and story has sage, the creosote occupies about seven times as much land as sage in Arizona and sometimes is mistaken for it by the uninitiate. While there are a number of types of creosote bush, in general, they are low growing, with dark green leaves, and occur either in pure or mixed stands. Today are found in impervious, penetrable, or flooded lands, withstand drought well, and seen to thrive despite possible extremes of summer heat and winter cold. They range from about two feet to four feet or occasionally more in height. They do, however demand alkali-free soil.

Unfortunately, creosote is virtually worthless as forage. The only animal that makes any use of its is the rabbit, which occasionally nibbles at it. However, it is good ground cover to retain soil, and it also is an attractive plant, with shiny, lacquered, dark green leaves glistening in the desert sun. It produces a tiny, yellow, roselike flower and white, hairy seeds. When, in drier places in higher elevations, it is interspersed with bur sage, the sparkling dark green of the creosote and the silvery, feathery green of the sage make a lovely picture.

Creosote is replaced in the southeastern part of Arizona by a similar bush, black brush (Flourensia cernua). Quite like creosote in appearance, black brush grows in denser stands. It too occupies only alkali-free land.

Probably the most famous of native Arizona flora are the cacti. There are some fifteen genera of cacti, some seventy-two species and something like two thousand varieties. Among the more famous cacti is the giant saguaro (Carnegiea gigantea). Almost every writer who ever penned a piece about the Arizona desert has referred to this most unusual and largest of succulents as "the stalwart sentinel of the desert" or something equally forced and futile. The giant saguaro is a plant unique in appearance and in the effect it has on the beholder. The only description is an actual firsthand acquaintance with a forest of these imposing, dignified, and sometimes ludicrously posed giants.

The saguaro is an extremely slow-growing plant. At the age of nearly ten years it may be only four inches high. After three decades its will have reached only between three and six feet in height. At age about seventy-five, the saguaro will be something over twelve feet tall and will begin to put forth its arms. Its is mature at something well over a century old, and at full maturity will have attained as much as fifty feet in Heights and will have put forth as many as fifty arms.

The root system of the saguaro at maturity is said to extend as much as sixty-five feet in all directions from the stalk. It has remarkable ability to gather and store water, a trait characteristic of most cacti. The saguaro's beautiful, white, waxy flower has been adopted as the Arizona state flower. It blooms in May or June usually, and by mid-summer has produced a fruit with watermelon-red pulp which was highly prized by the Indians and the early Spanish explorers and settlers as food. It was eaten raw or stored as syrup or preserves.

The saguaro is inhabited by desert birds. First, a little desert woodpecker cuts through the outer rim of the cactus, moves in and hollows out a cave inside. The saguaro immediately excretes a corklike substance which coats and heals the wounds, leading the woodpecker a comfortable, cork-insulated apartment.

But the woodpecker moves out at the end of the season and will not return to that home. Thus again is created a vacancy which other birds are very willing to fill. Most frequently it is the tiny elf owl, scarcely bigger than a sparrow, who moves in and takes up semi-permanent residence. Other birds also avail themselves of the saguaro homes built by woodpeckers.

This incursion of the birds apparently does the saguaro no harm; indeed, in nature's subtle and intricate plans, it might even benefit the plant. In return for the giant's hospitality, the woodpecker seems to know that during the rainy season even a small scratch might cause a huge saguaro to "bleed" to death. Thus the birds cut their holes and dig their caves only in dry weather. It has been noted by more than one desert lover that some humans with penknives and a penchant for seeing their names in public places, have killed the handiwork of centuries by failing to know as much as a bird.

......Complete books could be and have been written about the flora of the Arizona desert. Its plant Life is amazingly varied and abundant. Indeed, one of the greatest thrills for the newcomer to Arizona is his first sight of the desert in bloom. From late April in the warmer sections, to late June in cooler regions, the desert is a living easier of perfect, waxy blooms; of tiny bell-like flowers in luxuriant clusters; of towering stalks of flowers; of variegated foliage; of colors ranging from the brilliant to the soft pastel; of endless variety and never-ending delight. After a good rainy season, the blooms are particular rich.

For anyone--oldtimer or newcomer--who ever has been on the Arizona desert during or after a rain, a wonderful, life-long memory will be the haunting, spicy smell of the wet desert. Nowhere else in the world is there an odor like it--tangy, rich, rare, heady--compounded of the spices of all the herbs and shrubs and trees returning to life under the ministration of life-giving water.

...... Unusual, a state with such variety of climate and flora is is going to have a parallel variety in fauna, indeed Arizona is outstanding among states in its range of animal life. It boasts large game animals, large predators, many rodents, great variety of bird life, almost a unique set of reptiles, and myriad types of insects.

Many biologists in the past have stoutly maintained that each vegetation type has its distinct animal associates; change of plant life brings change of animal species. This may be true in large part in most places; but, characteristically, Arizona breaks the rule.

The outstanding breaker of this rule happens to be the animal which most often is thought of as a sort of symbol of the West, the antelope. Traditionally, the antelope is a creature of the grasslands; but in Arizona he is found on the high open grass plateaus, in the more open yellow pine forests, in the mesquite and cactus desert, and even down among the sand dunes and tide beaches of the Gulf of California, a few miles outside of Arizona's borders.

Another large game animal of Arizona defies similarly the rule of plant-animal association. This is the mule deer which ranges widely through the yellow pine forests of the northern part of the state, yet which occupies a very different type of range in the river bottoms of the southern part of the state. The mule deer and its cousin, Arizona's little whitetail, further beget paradoxes by reversing the elevations of their respective ranges in the northern and southern halves of the state. In the North, the mule deer prefer areas a thousand to three thousand feet above the range of the whitetail, whereas in the southern section, the weighttail range from immediately above to as much as four thousand feet above the mule deer.

Another unorthodox big game animal in Arizona is the Rocky Mountain Bighorn sheep. He's supposed to occupy rocky peaks of mountain ranges, as indeed he does in most places. In Arizona, however, he spends the winter and early spring in the sand and adobe flats, most unusual behavior for the Bighorn.

Biologists have discussed the question of behavior unorthodoxy in Arizona's big game mammals and have evolved some interesting theories to account for it. However, they have not reached any final conclusions, except that it is always easy to amaze a newly arrived biologist by taking him out and showing him a mule deer happily browsing quaking aspen at nine thousand feet in the Kaibab forest, and another mule deer gingerly nuzzling the fruit from among the savage spines of barrel cactus on a hot, dry desert flat only a little over a hundred feet above sea level. Or show him one Rocky Mountain sheep enjoying the cool breezes in the pines up on an eight thousand foot peak of the Santa Catalina Mountains; then take him down to the desert some six thousand feet lower and forty degrees hotter and show him another of the identical species bedded down on a dry sandy wash under an ironwood tree. Many biologist have to see it to believe it.

When the first white man came into what is now Arizona, they found here six indigenous species of cloven-hoofed animals: the two species of deer; Elk; pronghorn antelope; Rocky Mountain sheep; and peccary (javelina or wild pig). All of the original species are present today except the Elk. The native Arizona Elk was Merriam's Elk, Cervus merriami. This species was hunted to extinction and has been replaced by the assignments of a number of American Elk imported from Yellowstone Park and Jackson Hole, Wyoming. These substitutes, Cervus canadenis canadensis, have prospered in the habitat of their predecessors, the Mogollon Plateau, and have multiplied so rapidly they are now subject to legal hunting seasons. There are also growing herds in the Hualapai Mountains and in the vicinity of Bill Williams Mountain, started with a few imports. Recently it has been reported that Elk have crossed the Verde Valley from the Mogollon Rim to take up residents on Mingus Mountain and neighboring slopes.

Many years ago the population of antelope in Arizona was tremendous. Almost every mesa and grassy woodland and valley supported thousands of head of these animals. The Arizona antelope is of the American antelope family. This is a unique animal in that it is the only antelope in the world which sheds the horny coverings of its horns each year. Both sexes have horns, although the of that female are much smaller than those of the male. After mating season in the fall, the horny shell of the horns falls off, exposing a dark skin which covers a bony core underneath. A new shell begins to harden, and, as it does, coarse hair embedded in the skin drops away. The American, or pronghorn, antelope as found in Arizona is unique also in that it is the only antelope in the world with a forked, or pronged horn.

The species in Arizona is divided into two sub-species, the American pronghorn and the Mexican pronghorn. The biological name of the former is Antilocapra americana americana. The Mexican pronghorn is the Antilocapra americana mexicana. The American pronghorn is found in the open pine tablelands and grassy plateaus of the north, while its Mexican counterpart inhabits the desert and southern grasslands mesas.

Today, sizable herds of antelope are found in northern Arizona southeast and north of plateaus and north of Kingman, Seligman, and Ashfork. Smaller herds are scattered from the Grand Canyon to Prescott. Frequently the tourist driving between Prescott and Mingus Mountain is treated to the sight of groups of antelope close to the highway ranging freely along the whiteface Hereford cattle. The antelope of southern Arizona is concentrated principally in Pima and Cochise counties and Yuma County. They also into Sonora and show a marked migratory habit, ranging far south to follow rains and succulent forage. The antelope is one of the most gregarious animals in the world. Like the bison, the antelope can to congregate in great herds, and frequently in winter all the individuals from miles around gather into one band and stay together for periods of months.

The Bighorn sheep of Arizona is of the Nelson or Desert Bighorn type in the western third of the state north of the Bill Williams River, in the canyons of the Colorado River and its tributaries, and in all the desert Mountain ranges below yellow pine allegation. In the southern area, the range dose in an ever-widening arc eastward, marked by the Bradshaw, Mazatzal, Pinal, and Peloncillo Mountain toward the New Mexico state lines to. Southward it extends to the Mexican border except in southern Yuma County where the native species is the short-haired, pale item colored Gaillard Bighorn. The Nelson or Desert Bighorn is the Ovis canadensis nelsoni. The Gaillard Bighorn is the Ovis canadensis gaillardi.

The Bighorn sheep is a beautiful, amber-eyed animal. According to A. A. Nichol (ibid.; Large Game Metals; p. 60 et seq.), it is a true sheep, but it has hair instead of wool, and both sexes have horns. The horns of the rams are massive and curling, and in mature individuals measure as much as forty or more inches on the outside curve. Ewes have smaller horns. A mature male will weigh up to three hundred pounds, and females sometimes reach 175 pounds. The lambing season is early spring, and on some inaccessible and well protected ledge or rock, the ewe will care for one or two lambs.

The Bighorn has been protected for years by the inaccessibility and remoteness of its haunts. Thus, despite some popular apprehension for the species, the Bighorn is holding its own in Arizona. These sheep derive much of their water needs from cactus, but necessarily occasionally they have to know to water holes, a fact which makes them subject to the encroachment of the poacher. There has been no open season on Bighorns for several years.

Principal enemies of the Bighorn sheep have been eagles which prey on the lambs, mountain lions which prey on both lambs and mature animals, and, of course, man, who, despite laws to the contrary, for many years has practiced water-hole hunting which does decrease the number of the flocks. However Bighorn still are found in reasonably good numbers in Arizona, and there seems to be little if any danger of their extinction.

The smallest of the mammals in Arizona which are classified as big game is the peccary, also called the javelina, or wild pig. These peccaries are are not true pigs. They have a dorsal musk gland and other differences which distinguish them from the true pig, but their behavior and appearance resembles to a degree the domestic swine. These animals, like the bison and the antelope, are gregarious and run in packs. Their activities are markedly communal, and the individuals animal has a distinctly individual character. The peccary, despite a reputation for savageness, prefers to run away from danger. However, if the young are threatened or the safety of the herd appears in danger, the animals will fight ferociously. Remarkably quick and agile, the peccary when charging, is a most difficult foe to elude.

Enemies of the peccary, as of most animal life in Arizona, include the coyote. Don Coyote occasionally can outwit peccaries, but equally often the coyote loses. There are few other animals in the state that deliberately challenge a herd of peccaries.

Surprisingly enough the peccary makes an excellent and entertaining pet if captured while very young. Clean and intelligent, they become one-man pets to as high a degree as the best trained dog, and a well-trained peccary is worth a dozen police dogs for protection.

The female peccary is a grizzled gray in appearance. She will produce two red-haired youngsters at almost any season of the year. One frequently sees these babies running with the herd when they are not much over six inches high.

Peccaries are omnivorous. They subsist on roots, fruits, leaves, lizards, frogs, and insects. Often in the desert one will find the shallow, laterally running roots of the prickly pear nosed out, the work of the peccary in search of insects, for the prickly pear roots often have attached to them a considerable number of cicada and June beetle grubs. Peccaries in Arizona prefer the rough foothills of the southern ranges between one thousand and four thousand feet in elevation.

Another Arizona mammal sometimes classified as big game and sometimes as a predator is the black or brown bear. This is the bear whose biological name is Euarctos americanus amblyceps. It is found in the forested areas of the state, although in many of its native habitats, the animal has been exterminated. From year to year, or at least from half decade to half decade, the bear population of Arizona varies so greatly that the hunting of bears is governed by flexible rules. When the bear population in a given area becomes so great that it constitutes a menace to domestic stock, the State Game and Fish Commission will allow bear to be hunted. In other areas, bears are protected and, it is to be hoped that the population of will become reestablished on a more general range.

Bears are, of course, omnivorous. They eat fruit, grass, roots, berries, honey, fish, frogs, carrion, insects, and anything else that they find. Typically a hibernating animal, at least in colder climates, the black or brown bear in southern Arizona's mild winters seems not to hibernate, even in the mountains. At maturity, these bears will reach 450-475 pounds in weight. On the Mogollon Rim and the forested areas of the Mogollon Plateau, it is not infrequent for hunters in deer season and Elk season to see a black bear. Very occasionally one of these bears will become a confirmed killer of young domestic stock, and when this happens state and federal hunters respond to the rancher's need by going out with dogs and hunting the offending individual.

There are some people who believe that the buffalo is native to Arizona. More properly called the bison, this animal has not been native to Arizona since prehistoric times. The great bison herds of western history mostly inhabited the tremendous Great Plains area of Texas and north. Even when the earliest Spaniards were ensconced in Tigeux in northwestern New Mexico, during the sixteenth century, they made special trips to the East to the plains of Kansas to hunt buffalo. Apparently even in those days the bison were not found in any concentrated numbers in the Southwest.

There have been in modern times some herds of buffalo in Arizona, however. One has existed for a number of years in Houserock Valley, north of the Colorado. Consisting of about 120 animals, it is owned by the state of Arizona, although it originally was established on the Kaibab Plateau by a private citizen for personal enjoyment. Some of the animals broke out of pasture and migrated to the lower valleys. There they crossbred with domestic beef cattle and produced a most ludicrous looking offspring which became known locally as the "cattlelo." Fair also was another herd at Fort Huachuca for a number of years; but when the fort was reactivated as one of the nation's great electronic proving grounds, the federal government and the state of Arizona removed these animals for their own protection.

The large game animals of Arizona are not its only large wild animals. There is another class of animal perhaps even more interesting than the game animals. These are the large predators.

For a number of years there have been no grizzly bears in Arizona, although at one time grizzlies were present in the White Mountains. All the rest of the large predators occurring in the state belong either to the cat or dog tribe. Most important of these is the mountain lion. The mountain lion is the same animal as that called cougar, puma, panther, and painter. It is also, in works of fiction, called the catamount. A close relative of the African lion, the Arizona lion is divided into two varieties, the Mexican cougar and the Yuma. The Mexican cougar is known as the Felis oregonensis californica. The Yuma is the Felis oregonensis browni.

The role of the mountain lion in Arizona has been an important one. Not only has he inspired writers of western fiction to glorify his deeds, sometimes perhaps to vilify him; he has also contributed largely to the balance of nature in the state. Between 1907 and 1919 hunters killed over 600 lions in the Kaibab Forest and Game Preserve alone at a rate of approximately 50 lions a year. Considering the fact that deer were originally the principal part of the diet of mountain lions, it is readily observed that this many lions in one forest was a major factor in maintaining the deer herd at a given level. This natural check on the population of deer, antelope and so on was removed from the forests by constant hunting by the white man. This hunting was prompted by the fact that the diet of mountain lions changed after the white man brought cattle, sheep, and horses into the mountain ranges. The domestic stock being less wary and less able to take care of itself, naturally fell easier prey to the lion. Having caused widespread stock losses, the lion naturally soon became the object of the white man's hunt. Eventually too many hunters would near-eradicate the lion. The commoner of the two species of mountain lion in Arizona by far is the Mexican cougar. He ranges throughout the entire state with the possible exception of the open treeless valleys and mesas. The Yuma lion, a somewhat smaller and paler animal, on the other hand, is found mostly south of the Bill Williams River, through Yuma County and western Pima County. While the Mexican cougar now has expanded his diet to include cattle, sheep, and horses as well as game animals, the Yuma lion consumes a diet principally of burro deer, a small deer of the southern part of the state, mountain sheep, antelope, and wild burros appeared both the subspecies kill colts, calves, lambs and other prey indiscriminately. Fully grown, the mountain lion of Arizona will wait from 175 pounds to 200. A good-sized male will measure eight feet in length, although longer and larger specimens are not too rare.

The typical Mexican cougar is an exceedingly graceful animal, pale brown to gray in color. The ears and tip of the tail are dark. The young kittens are spotted irregularly with black dots about the size of a twenty-five cent piece. A a normal litter consists of one to five young, born in some rocky crevice or shallow cave. The mountain lion will whelp almost any month of the year.

The lion is naturally afraid of man, and there are few if any offense cases on record in which the Arizona mountain lion has attacked and killed a human being. This shyness in the presence of man also makes it very difficult for man to see a mountain lion unless that lion is flushed by gods. The average lion will range some thirty to forty miles in radius from the den.

Two other important large predators of Arizona distantly to the mountain lion are the lynx, and the bobcat. These both are members of the short-hailed wild cats represented in the northern and colder regions and the southern and warmer regions. The lynx is more commonly found in the cooler areas, the bobcat in the warmer.

The three cats mentioned so far are all indigenous to Arizona. However, two other members of the cat family are occasional visitors from Mexico. One of these is "El Tigre," or the jaguar of Mexico. The most northern record of a jaguar's having been taken in Arizona is the animal that was killed several years ago at the Grand Canyon. Others have been killed in the mountains in Southern Arizona. "El Tigre is a magnificent animal, powerful, less timid than the lion, and not so furtive. It's coat is a rich tan with yellow field heavily marked with black rosettes. "El Tigre" has earned a special respect among the natives of Mexico, and on occasion they have named a general or a bandit whom they admire "El Tigre," after this large and fearless animal.

The second Mexican migrant is the small, graceful ocelot, or tiger cat. This animal, no larger than the typical bobcat, is a surprisingly mild-mannered and calm member of the cat family. Very rarely black individuals of this animal are found; but normally the coat is buff or gray with abundant elongated black markings.

To Be Continued!