Report on the lands of the arid region of the United States, with a more detailed account of the lands of Utah

The eastern portion of the United States is supplied with abundant rainfall for agricultural purposes, receiving the necessary amount from the evaporation of the Atlantic Ocean and the Gulf of Mexico; but westward the amount of aqueous precipitation diminishes in a general way until at last a region is reached where the climate is so arid that agriculture is not successful without irrigation. This Arid Region begins about midway in the Great Plains and extends across the Rocky Mountains to the Pacific Ocean. But on the northwest coast there is a region of greater precipitation, embracing western Washington and Oregon and the northwest corner of California. The winds impinging on this region are freighted with moisture derived from the great Pacific currents; and where this water-laden atmosphere strikes the western coast in full force, the precipitation is excessive, reaching a maximum north of the Columbia River of 80 inches annually. But the rainfall rapidly decreases from the Pacific Ocean eastward to the summit of the Cascade Mountains. It will be convenient to designate this humid area as the Lower Columbia Region. Rain gauge records have not been made to such an extent as to enable us to define its eastern and southern boundaries, but as they are chiefly along high mountains, definite boundary lines are unimportant in the consideration of agricultural resources and the questions relating thereto. In like manner on the east the rain gauge records, though more full, do not give all the facts necessary to a thorough discussion of the subject; yet the records are such as to indicate approximately the boundary between the Arid Region, where irrigation is necessary to agriculture, and the Humid Region, where the lands receive enough moisture from the clouds for the maturing of crops. Experience teaches that it is not wise to depend upon rainfall where the amount is less than 20 inches annually, if this amount is somewhat evenly distributed throughout the year; but if the rainfall is unevenly distributed, so that “rainy seasons” are produced, the question whether agriculture is possible without irrigation depends upon the time of the “rainy season” and the amount of its rainfall. Any unequal distribution of rain through the year, though the inequality be so slight as not to produce “rainy seasons”, affects agriculture either favorably or unfavorably. If the spring and summer precipitation exceeds that of the fall and winter, a smaller amount of annual rain may be sufficient; but if the rainfall during the season of growing crops is less than the average of the same length of time during the remainder of the year, a greater amount of annual precipitation is necessary. In some localities in the western portion of the United States this unequal distribution of rainfall through the seasons affects agriculture favorably, and this is true immediately west of the northern portion of the line of 20 inches of rainfall, which extends along the plains from our northern to our southern boundary.

The isohyetal or mean annual rainfall line of 20 inches, as indicated on the rain chart accompanying this report, begins on the southern boundary of the United States, about 60 miles west of Brownsville, on the Rio Grande del Norte, and intersects the northern boundary about 50 miles east of Pembina. Between these two points the line is very irregular, but in middle latitudes makes a general curve to the westward. On the southern portion of the line the rainfall is somewhat evenly distributed through the seasons, but along the northern portion the rainfall of spring and summer is greater than that of fall and winter, and hence the boundary of what has been called the Arid Region runs farther to the west. Again, there is another modifying condition, namely, that of temperature. Where the temperature is greater, more rainfall is needed; where the temperature is less, agriculture is successful with a smaller amount of precipitation. But geographically this temperature is dependent upon two conditions—altitude and latitude. Along the northern portion of the line latitude is an important factor, and the line of possible agriculture without irrigation is carried still farther westward. This conclusion, based upon the consideration of rainfall and latitude, accords with the experience of the farmers of the region, for it is a well known fact that agriculture without irrigation is successfully carried on in the valley of the Red River of the North, and also in the southeastern portion of Dakota Territory. A much more extended series of rain-gauge records than we now have is necessary before this line constituting the eastern boundary of the Arid Region can be well defined. It is doubtless more or less meandering in its course throughout its whole extent from south to north, being affected by local conditions of rainfall, as well as by the general conditions above mentioned; but in a general way it may be represented by the one hundredth meridian, in some places passing to the east, in others to the west, but in the main to the east.

The limit of successful agriculture without irrigation has been set at 20 inches, that the extent of the Arid Region should by no means be exaggerated; but at 20 inches agriculture will not be uniformly successful from season to season. Many droughts will occur; many seasons in a long series will be fruitless; and it may be doubted whether, on the whole, agriculture will prove remunerative. On this point it is impossible to speak with certainty. A larger experience than the history of agriculture in the western portion of the United States affords is necessary to a final determination of the question.

In fact, a broad belt separates the Arid Region of the west from the Humid Region of the east. Extending from the one hundredth meridian eastward to about the isohyetal line of 28 inches, the district of country thus embraced will be subject more or less to disastrous droughts, the frequency of which will diminish from west to east. For convenience let this be called the Sub-humid Region. Its western boundary is the line already defined as running irregularly along the one hundredth meridian. Its eastern boundary passes west of the isohyetal line of 28 inches of rainfall in Minnesota, running approximately parallel to the western boundary line above described. Nearly one-tenth of the whole area of the United States, exclusive of Alaska, is embraced in this Sub-humid Region. In the western portion disastrous droughts will be frequent; in the eastern portion infrequent. In the western portion agriculturists will early resort to irrigation to secure immunity from such disasters, and this event will be hastened because irrigation when properly conducted is a perennial source of fertilization, and is even remunerative for this purpose alone; and for the same reason the inhabitants of the eastern part will gradually develop irrigating methods. It may be confidently expected that at a time not far distant irrigation will be practiced to a greater or less extent throughout this Sub-humid Region. Its settlement presents problems differing materially from those pertaining to the region to the westward. Irrigation is not immediately necessary, and hence agriculture does not immediately depend upon capital. The region may be settled and its agricultural capacities more or less developed, and the question of the construction of irrigating canals may be a matter of time and convenience. For many reasons, much of the sub-humid belt is attractive to settlers: it is almost destitute of forests, and for this reason is more readily subdued, as the land is ready for the plow. But because of the lack of forests the country is more dependent upon railroads for the transportation of building and fencing materials and for fuel. To a large extent it is a region where timber may be successfully cultivated. As the rainfall is on a general average nearly sufficient for continuous successful agriculture, the amount of water to be supplied by irrigating canals will be comparatively small, so that its streams can serve proportionally larger areas than the streams of the Arid Region. In its first settlement the people will be favored by having lands easily subdued, but they will have to contend against a lack of timber. Eventually this will be a region of great agricultural wealth, as in general the soils are good. From our northern to our southern boundary no swamp lands are found, except to some slight extent in the northeastern portion, and it has no excessively hilly or mountainous districts. It is a beautiful prairie country throughout, lacking somewhat in rainfall; but this want can be easily supplied by utilizing the living streams; and, further, these streams will afford fertilizing materials of great value.

The Humid Region of the lower Columbia and the Sub-humid Region of the Great Plains have been thus briefly indicated in order that the great Arid Region, which is the subject of this paper, may be more clearly defined.

THE ARID REGION.

The Arid Region is the great Rocky Mountain Region of the United States, and it embraces something more than four-tenths of the whole country, excluding Alaska. In all this region the mean annual rainfall is insufficient for agriculture, but in certain seasons some localities, now here, now there, receive more than their average supply. Under such conditions crops will mature without irrigation. As such seasons are more or less infrequent even in the more favored localities, and as the agriculturist cannot determine in advance when such seasons may occur, the opportunities afforded by excessive rainfall cannot be improved.

In central and northern California an unequal distribution of rainfall through the seasons affects agricultural interests favorably. A “rainy season” is here found, and the chief precipitation occurs in the months of December-April. The climate, tempered by mild winds from the broad expanse of Pacific waters, is genial, and certain crops are raised by sowing the seeds immediately before or during the “rainy season”, and the watering which they receive causes the grains to mature so that fairly remunerative crops are produced. But here again the lands are subject to the droughts of abnormal seasons. As many of these lands can be irrigated, the farmers of the country are resorting more and more to the streams, and soon all the living waters of this region will be brought into requisition.

In the tables of a subsequent chapter this will be called the San Francisco Region.

Again in eastern Washington and Oregon, and perhaps in northern Idaho, agriculture is practiced to a limited extent without irrigation. The conditions of climate by which this is rendered possible are not yet fully understood. The precipitation of moisture on the mountains is greater than on the lowlands, but the hills and mesas adjacent to the great masses of mountains receive a little of the supply condensed by the mountains themselves, and it will probably be found that limited localities in Montana, and even in Wyoming, will be favored by this condition to an extent sufficient to warrant agricultural operations independent of irrigation. These lands, however, are usually supplied with living streams, and their irrigation can be readily effected, and to secure greater certainty and greater yield of crops irrigation will be practiced in such places.

IRRIGABLE LANDS.

Within the Arid Region only a small portion of the country is irrigable. These irrigable tracts are lowlands lying along the streams. On the mountains and high plateaus forests are found at elevations so great that frequent summer frosts forbid the cultivation of the soil. Here are the natural timber lands of the Arid Region—an upper region set apart by nature for the growth of timber necessary to the mining, manufacturing, and agricultural industries of the country. Between the low irrigable lands and the elevated forest lands there are valleys, mesas, hills, and mountain slopes bearing grasses of greater or less value for pasturage purposes.

Then, in discussing the lands of the Arid Region, three great classes are recognized—the irrigable lands below, the forest lands above, and the pasturage lands between. In order to set forth the characteristics of these lands and the conditions under which they can be most profitably utilized, it is deemed best to discuss first a somewhat limited region in detail as a fair type of the whole. The survey under the direction of the writer has been extended over the greater part of Utah, a small part of Wyoming and Colorado, the northern portion of Arizona, and a small part of Nevada, but it is proposed to take up for this discussion only the area embraced in Utah Territory.

In Utah Territory agriculture is dependent upon irrigation. To this statement there are some small exceptions. In the more elevated regions there are tracts of meadow land from which small crops of hay can be taken: such lands being at higher altitudes need less moisture, and at the same time receive a greater amount of rainfall because of the altitude; but these meadows have been, often are, and in future will be, still more improved by irrigation. Again, on the belt of country lying between Great Salt Lake and the Wasatch Mountains the local rainfall is much greater than the general rainfall of the region. The water evaporated from the lake is carried by the westerly winds to the adjacent mountains on the east and again condensed, and the rainfall thus produced extends somewhat beyond the area occupied by the mountains, so that the foot hills and contiguous bench lands receive a modicum of this special supply. In some seasons this additional supply is enough to water the lands for remunerative agriculture, but the crops grown will usually be very small, and they will be subject to seasons of extreme drought, when all agriculture will result in failure. Most of these lands can be irrigated, and doubtless will be, from a consideration of the facts already stated, namely, that crops will thereby be greatly increased and immunity from drought secured. Perhaps other small tracts, on account of their subsoils, can be profitably cultivated in favorable seasons, but all of these exceptions are small, and the fact remains that agriculture is there dependent upon irrigation. Only a small part of the territory, however, can be redeemed, as high, rugged mountains and elevated plateaus occupy much of its area, and these regions are so elevated that summer frosts forbid their occupation by the farmer. Thus thermic conditions limit agriculture to the lowlands, and here another limit is found in the supply of water. Some of the large streams run in deep gorges so far below the general surface of the country that they cannot be used; for example, the Colorado River runs through the southeastern portion of the Territory and carries a great volume of water, but no portion of it can be utilized within the Territory from the fact that its channel is so much below the adjacent lands. The Bear River, in the northern part of the Territory, runs in a somewhat narrow valley, so that only a portion of its waters can be utilized. Generally the smaller streams can be wholly employed in agriculture, but the lands which might thus be reclaimed are of greater extent than the amount which the streams can serve; hence in all such regions the extent of irrigable land is dependent upon the volume of water carried by the streams.

In order to determine the amount of irrigable land in Utah it was necessary to determine the areas to which the larger streams can be taken by proper engineering skill, and the amount which the smaller streams can serve. In the latter case it was necessary to determine first the amount of land which a given amount or unit of water would supply, and then the volume of water running in the streams; the product of these factors giving the extent of the irrigable lands. A continuous flow of one cubic foot of water per second was taken as the unit, and after careful consideration it was assumed that this unit of water will serve from 80 to 100 acres of land. Usually the computations have been made on the basis of 100 acres. This unit was determined in the most practical way—from the experience of the farmers of Utah who have been practicing agriculture for the past thirty years. Many of the farmers will not admit that so great a tract can be cultivated by this unit. In the early history of irrigation in this country the lands were oversupplied with water, but experience has shown that irrigation is most successful when the least amount of water is used necessary to a vigorous growth of the crops; that is, a greater yield is obtained by avoiding both scanty and excessive watering; but the tendency to overwater the lands is corrected only by extended experience. A great many of the waterways are so rudely constructed that much waste ensues. As irrigating methods are improved this wastage will be avoided; so in assuming that a cubic foot of water will irrigate from 80 to 100 acres of land it is at the same time assumed that only the necessary amount of water will be used, and that the waterways will eventually be so constructed that the waste now almost universal will be prevented.

In determining the volume of water flowing in the streams great accuracy has not been attained. For this purpose it would be necessary to make continuous daily, or even hourly, observations for a series of years on each stream, but by the methods described in the following chapters it will be seen that a fair approximation to a correct amount has been made. For the degree of accuracy reached much is due to the fact that many of the smaller streams are already used to their fullest capacity, and thus experience has solved the problem.

Having determined from the operations of irrigation that one cubic foot per second of water will irrigate from 80 to 100 acres of land when the greatest economy is used, and having determined the volume of water or number of cubic feet per second flowing in the several streams of Utah by the most thorough methods available under the circumstances, it appears that within the territory, excluding a small portion in the southeastern corner where the survey has not yet been completed, the amount of land which it is possible to redeem by this method is about 2,262 square miles, or 1,447,920 acres. Of course this amount does not lie in a continuous body, but is scattered in small tracts along the water courses. For the purpose of exhibiting their situations a map of the territory has been prepared, and will be found accompanying this report, on which the several tracts of irrigable lands have been colored. A glance at this map will show how they are distributed. Excluding that small portion of the territory in the southeast corner not embraced in the map, Utah has an area of 80,000 square miles, of which 2,262 square miles are irrigable. That is, 2.8 per cent. of the lands under consideration can be cultivated by utilizing all the available streams during the irrigating season.

In addition to the streams considered in this statement there are numerous small springs on the mountain sides scattered throughout the territory—springs which do not feed permanent streams; and if their waters were used for irrigation the extent of irrigable land would be slightly increased; to what exact amount cannot be stated, but the difference would be so small as not to materially affect the general statement, and doubtless these springs can be used in another way and to a better purpose, as will hereafter appear.

This statement of the facts relating to the irrigable lands of Utah will serve to give a clearer conception of the extent and condition of the irrigable lands throughout the Arid Region. Such as can be redeemed are scattered along the water courses, and are in general the lowest lands of the several districts to which they belong. In some of the states and territories the percentage of irrigable land is less than in Utah, in others greater, and it is probable that the percentage in the entire region is somewhat greater than in the territory which we have considered.

The Arid Region is somewhat more than four-tenths of the total area of the United States, and as the agricultural interests of so great an area are dependent upon irrigation it will be interesting to consider certain questions relating to the economy and practicability of distributing the waters over the lands to be redeemed.

ADVANTAGES OF IRRIGATION.

There are two considerations that make irrigation attractive to the agriculturist. Crops thus cultivated are not subject to the vicissitudes of rainfall; the farmer fears no droughts; his labors are seldom interrupted and his crops rarely injured by storms. This immunity from drought and storm renders agricultural operations much more certain than in regions of greater humidity. Again, the water comes down from the mountains and plateaus freighted with fertilizing materials derived from the decaying vegetation and soils of the upper regions, which are spread by the flowing water over the cultivated lands. It is probable that the benefits derived from this source alone will be full compensation for the cost of the process. Hitherto these benefits have not been fully realized, from the fact that the methods employed have been more or less crude. When the flow of water over the land is too great or too rapid the fertilizing elements borne in the waters are carried past the fields, and a washing is produced which deprives the lands irrigated of their most valuable elements, and little streams cut the fields with channels injurious in diverse ways. Experience corrects these errors, and the irrigator soon learns to flood his lands gently, evenly, and economically. It may be anticipated that all the lands redeemed by irrigation in the Arid Region will be highly cultivated and abundantly productive, and agriculture will be but slightly subject to the vicissitudes of scant and excessive rainfall.

A stranger entering this Arid Region is apt to conclude that the soils are sterile, because of their chemical composition, but experience demonstrates the fact that all the soils are suitable for agricultural purposes when properly supplied with water. It is true that some of the soils are overcharged with alkaline materials, but these can in time be “washed out”. Altogether the fact suggests that far too much attention has heretofore been paid to the chemical constitution of soils and too little to those physical conditions by which moisture and air are supplied to the roots of the growing plants.

COÖPERATIVE LABOR OR CAPITAL NECESSARY FOR THE DEVELOPMENT OF IRRIGATION.

Small streams can be taken out and distributed by individual enterprise, but coöperative labor or aggregated capital must be employed in taking out the larger streams.

The diversion of a large stream from its channel into a system of canals demands a large outlay of labor and material. To repay this all the waters so taken out must be used, and large tracts of land thus become dependent upon a single canal. It is manifest that a farmer depending upon his own labor cannot undertake this task. To a great extent the small streams are already employed, and but a comparatively small portion of the irrigable lands can be thus redeemed; hence the chief future development of irrigation must come from the use of the larger streams. Usually the confluence of the brooks and creeks which form a large river takes place within the mountain district which furnishes its source before the stream enters the lowlands where the waters are to be used. The volume of water carried by the small streams that reach the lowlands before uniting with the great rivers, or before they are lost in the sands, is very small when compared with the volume of the streams which emerge from the mountains as rivers. This fact is important. If the streams could be used along their upper ramifications while the several branches are yet small, poor men could occupy the lands, and by their individual enterprise the agriculture of the country would be gradually extended to the limit of the capacity of the region; but when farming is dependent upon larger streams such men are barred from these enterprises until coöperative labor can be organized or capital induced to assist. Before many years all the available smaller streams throughout the entire region will be occupied in serving the lands, and then all future development will depend on the conditions above described.

In Utah Territory coöperative labor, under ecclesiastical organization, has been very successful. Outside of Utah there are but few instances where it has been tried; but at Greeley, in the State of Colorado, this system has been eminently successful.

THE USE OF SMALLER STREAMS SOMETIMES INTERFERES WITH THE USE OF THE LARGER.

A river emerging from a mountain region and meandering through a valley may receive small tributaries along its valley course. These small streams will usually be taken out first, and the lands which they will be made to serve will often lie low down in the valley, because the waters can be more easily controlled here and because the lands are better; and this will be done without regard to the subsequent use of the larger stream to which the smaller ones are tributary. But when the time comes to take out the larger stream, it is found that the lands which it can be made to serve lying adjacent on either hand are already in part served by the smaller streams, and as it will not pay to take out the larger stream without using all of its water, and as the people who use the smaller streams have already vested rights in these lands, a practical prohibition is placed upon the use of the larger river. In Utah, church authority, to some extent at least, adjusts these conflicting interests by causing the smaller streams to be taken out higher up in their course. Such adjustment is not so easily attained by the great body of people settling in the Rocky Mountain Region, and some provision against this difficulty is an immediate necessity. It is a difficulty just appearing, but in the future it will be one of great magnitude.

INCREASE OF IRRIGABLE AREA BY THE STORAGE OF WATER.

Within the Arid Region great deposits of gold, silver, iron, coal, and many other minerals are found, and the rapid development of these mining industries will demand pari passu a rapid development of agriculture. Thus all the lands that can be irrigated will be required for agricultural products necessary to supply the local market created by the mines. For this purpose the waters of the non-growing season will be stored, that they may be used in the growing season.

There are two methods of storing the waste waters. Reservoirs may be constructed near the sources of the streams and the waters held in the upper valleys, or the water may be run from the canals into ponds within or adjacent to the district where irrigation is practiced. This latter method will be employed first. It is already employed to some extent where local interests demand and favorable opportunities are afforded. In general, the opportunities for ponding water in this way are infrequent, as the depressions where ponds can easily be made are liable to be so low that the waters cannot be taken from them to the adjacent lands, but occasionally very favorable sites for such ponds may be found. This is especially true near the mountains where alluvial cones have been formed at the debouchure of the streams from the mountain cañons. Just at the foot of the mountains are many places where ancient glaciation has left the general surface with many depressions favorable to ponding.

Ponding in the lower region is somewhat wasteful of water, as the evaporation is greater than above, and the pond being more or less shallow a greater proportional surface for evaporation is presented. This wastage is apparent when it is remembered that the evaporation in an arid climate may be from 60 to 80 inches annually, or even greater.

Much of the waste water comes down in the spring when the streams are high and before the growing crops demand a great supply. When this water is stored the loss by evaporation will be small.

The greater storage of water must come from the construction of great reservoirs in the highlands where lateral valleys may be dammed and the main streams conducted into them by canals. On most streams favorable sites for such water works can be found. This subject cannot be discussed at any length in a general way, from the fact that each stream presents problems peculiar to itself.

It cannot be very definitely stated to what extent irrigation can be increased by the storage of water. The rainfall is much greater in the mountain than in the valley districts. Much of this precipitation in the mountain districts falls as snow. The great snow banks are the reservoirs which hold the water for the growing seasons. Then the streams are at flood tide; many go dry after the snows have been melted by the midsummer sun; hence they supply during the irrigating time much more water than during the remainder of the year. During the fall and winter the streams are small; in late spring and early summer they are very large. A day’s flow at flood time is greater than a month’s flow at low water time. During the first part of the irrigating season less water is needed, but during that same time the supply is greatest. The chief increase will come from the storage of this excess of water in the early part of the irrigating season. The amount to be stored will then be great, and the time of this storage will be so short that it will be but little diminished by evaporation. The waters of the fall and winter are so small in amount that they will not furnish a great supply, and the time for their storage will be so great that much will be lost by evaporation. The increase by storage will eventually be important, and it would be wise to anticipate the time when it will be needed by reserving sites for principal reservoirs and larger ponds.

TIMBER LANDS.

Throughout the Arid Region timber of value is found growing spontaneously on the higher plateaus and mountains. These timber regions are bounded above and below by lines which are very irregular, due to local conditions. Above the upper line no timber grows because of the rigor of the climate, and below no timber grows because of aridity. Both the upper and lower lines descend in passing from south to north; that is, the timber districts are found at a lower altitude in the northern portion of the Arid Region than in the southern. The forests are chiefly of pine, spruce, and fir, but the pines are of principal value. Below these timber regions, on the lower slopes of mountains, on the mesas and hills, low, scattered forests are often found, composed mainly of dwarfed piñon pines and cedars. These stunted forests have some slight value for fuel, and even for fencing, but the forests of principal value are found in the Timber Region as above described.

Primarily the growth of timber depends on climatic conditions—humidity and temperature. Where the temperature is higher, humidity must be greater, and where the temperature is lower, humidity may be less. These two conditions restrict the forests to the highlands, as above stated. Of the two factors involved in the growth of timber, that of the degree of humidity is of the first importance; the degree of temperature affects the problem comparatively little, and for most of the purposes of this discussion may be neglected. For convenience, all these upper regions where conditions of temperature and humidity are favorable to the growth of timber may be called the timber regions.

Not all these highlands are alike covered with forests. The timber regions are only in part areas of standing timber. This limitation is caused by fire. Throughout the timber regions of all the arid land fires annually destroy larger or smaller districts of timber, now here, now there, and this destruction is on a scale so vast that the amount taken from the lands for industrial purposes sinks by comparison into insignificance. The cause of this great destruction is worthy of careful attention. The conditions under which these fires rage are climatic. Where the rainfall is great and extreme droughts are infrequent, forests grow without much interruption from fires; but between that degree of humidity necessary for their protection, and that smaller degree necessary to growth, all lands are swept bare by fire to an extent which steadily increases from the more humid to the more arid districts, until at last all forests are destroyed, though the humidity is still sufficient for their growth if immunity from fire were secured. The amount of mean annual rainfall necessary to the growth of forests if protected from fire is probably about the same as the amount necessary for agriculture without irrigation; at any rate, it is somewhere from 20 to 24 inches. All timber growth below that amount is of a character so stunted as to be of little value, and the growth is so slow that, when once the timber has been taken from the country, the time necessary for a new forest growth is so great that no practical purpose is subserved.

The evidence that the growth of timber, if protected from fires, might be extended to the limits here given is abundant. It is a matter of experience that planted forests thus protected will thrive throughout the prairie region and far westward on the Great Plains. In the mountain region it may be frequently observed that forest trees grow low down on the mountain slopes and in the higher valleys wherever local circumstances protect them from fires, as in the case of rocky lands that give insufficient footing to the grass and shrubs in which fires generally spread. These cases must not be confounded with those patches of forest that grow on alluvial cones where rivers leave mountain cañons and enter valleys or plains. Here the streams, clogged by the material washed from the adjacent mountains by storms, are frequently turned from their courses and divided into many channels running near the surface. Thus a subterranean watering is effected favorable to the growth of trees, as their roots penetrate to sufficient depth. Usually this watering is too deep for agriculture, so that forests grow on lands that cannot be cultivated without irrigation.

Fire is the immediate cause of the lack of timber on the prairies, the eastern portion of the Great Plains, and on some portions of the highlands of the Arid Region; but fires obtain their destructive force through climatic conditions, so that directly and remotely climate determines the growth of all forests. Within the region where prairies, groves, and forests appear, the local distribution of timber growth is chiefly dependent upon drainage and soil, a subject which needs not be here discussed. Only a small portion of the Rocky Mountain Region is protected by climatic conditions from the invasion of fires, and a sufficiency of forests for the country depends upon the control which can be obtained over that destructive agent. A glance at the map of Utah will exhibit the extent and distribution of the forest region throughout that territory, and also show what portions of it are in fact occupied by standing timber. The area of standing timber, as exhibited on the map, is but a part of the Timber Region as there shown, and includes all of the timber, whether dense or scattered.

Necessarily the area of standing timber has been generalized. It was not found practicable to indicate the growth of timber in any refined way by grading it, and by rejecting from the general area the innumerable small open spaces. If the area of standing timber were considered by acres, and all acres not having timber valuable for milling purposes rejected, the extent would be reduced at least to one-fourth of that colored. Within the territory represented on the map the Timber Region has an extent of 18,500 square miles; that is, 23 per cent. belongs to the Timber Region. The general area of standing timber is about 10,000 square miles, or 12.5 per cent. of the entire area. The area of milling timber, determined in the more refined way indicated above, is about 2,500 square miles, or 3¹⁄₈ per cent. of the area embraced on the map. In many portions of the Arid Region these percentages are much smaller. This is true of southern California, Nevada, southern Arizona, and Idaho. In other regions the percentages are larger. Utah gives about a fair average. In general it may be stated that the timber regions are fully adequate to the growth of all the forests which the industrial interests of the country will require if they can be protected from desolation by fire. No limitation to the use of the forests need be made. The amount which the citizens of the country will require will bear but a small proportion to the amount which the fires will destroy; and if the fires are prevented, the renewal by annual growth will more than replace that taken by man. The protection of the forests of the entire Arid Region of the United States is reduced to one single problem—Can these forests be saved from fire? The writer has witnessed two fires in Colorado, each of which destroyed more timber than all that used by the citizens of that State from its settlement to the present day; and at least three in Utah, each of which has destroyed more timber than that taken by the people of the territory since its occupation. Similar fires have been witnessed by other members of the surveying corps. Everywhere throughout the Rocky Mountain Region the explorer away from the beaten paths of civilization meets with great areas of dead forests; pines with naked arms and charred trunks attesting to the former presence of this great destroyer. The younger forests are everywhere beset with fallen timber, attesting to the rigor of the flames, and in seasons of great drought the mountaineer sees the heavens filled with clouds of smoke.

In the main these fires are set by Indians. Driven from the lowlands by advancing civilization, they resort to the higher regions until they are forced back by the deep snows of winter. Want, caused by the restricted area to which they resort for food; the desire for luxuries to which they were strangers in their primitive condition, and especially the desire for personal adornment, together with a supply of more effective instruments for hunting and trapping, have in late years, during the rapid settlement of the country since the discovery of gold and the building of railroads, greatly stimulated the pursuit of animals for their furs—the wealth and currency of the savage. On their hunting excursions they systematically set fire to forests for the purpose of driving the game. This is a fact well known to all mountaineers. Only the white hunters of the region properly understand why these fires are set, it being usually attributed to a wanton desire on the part of the Indians to destroy that which is of value to the white man. The fires can, then, be very greatly curtailed by the removal of the Indians.

These forest regions are made such by inexorable climatic conditions. They are high among the summer frosts. The plateaus are scored by deep cañons, and the mountains are broken with crags and peaks. Perhaps at some distant day a hardy people will occupy little glens and mountain valleys, and wrest from an unwilling soil a scanty subsistence among the rigors of a sub-arctic climate. Herdsmen having homes below may in the summer time drive their flocks to the higher lands to crop the scanty herbage. Where mines are found mills will be erected and little towns spring up, but in general habitations will be remote. The forests will be dense here or scattered there, as the trees may with ease or difficulty gain a foothold, but the forest regions will remain such, to be stripped of timber here and there from time to time to supply the wants of the people who live below; but once protected from fires, the forests will increase in extent and value. The first step to be taken for their protection must be by prohibiting the Indians from resorting thereto for hunting purposes, and then slowly, as the lower country is settled, the grasses and herbage of the highlands, in which fires generally spread, will be kept down by summer pasturage, and the dead and fallen timber will be removed to supply the wants of people below. This protection, though sure to come at last, will be tardy, for it depends upon the gradual settlement of the country; and this again depends upon the development of the agricultural and mineral resources and the establishment of manufactories, and to a very important extent on the building of railroads, for the whole region is so arid that its streams are small, and so elevated above the level of the sea that its few large streams descend too rapidly for navigation.

AGRICULTURAL AND TIMBER INDUSTRIES DIFFERENTIATED.

It is apparent that the irrigable lands are more or less remote from the timber lands; and as the larger streams are employed for irrigation, in the future the extended settlements will be still farther away. The pasturage lands that in a general way intervene between the irrigable and timber lands have a scanty supply of dwarfed forests, as already described, and the people in occupying these lands will not resort, to any great extent, to the mountains for timber; hence timber and agricultural enterprises will be more or less differentiated; lumbermen and woodmen will furnish to the people below their supply of building and fencing material and fuel. In some cases it will be practicable for the farmers to own their timber lands, but in general the timber will be too remote, and from necessity such a division of labor will ensue.

CULTIVATION OF TIMBER.

In the irrigable districts much timber will be cultivated along the canals and minor waterways. It is probable that in time a sufficient amount will thus be raised to supply the people of the irrigable districts with fuel wherever such fuel is needed, but often such a want will not exist, for in the Rocky Mountain Region there is a great abundance of lignitic coals that may be cheaply mined. All these coals are valuable for domestic purposes, and many superior grades are found. These coals are not uniformly distributed, but generally this source of fuel is ample.

PASTURAGE LANDS.

The irrigable lands and timber lands constitute but a small fraction of the Arid Region. Between the lowlands on the one hand and the highlands on the other is found a great body of valley, mesa, hill, and low mountain lands. To what extent, and under what conditions can they be utilized? Usually they bear a scanty growth of grasses. These grasses are nutritious and valuable both for summer and winter pasturage. Their value depends upon peculiar climatic conditions; the grasses grow to a great extent in scattered bunches, and mature seeds in larger proportion perhaps than the grasses of the more humid regions. In general the winter aridity is so great that the grasses when touched by the frosts are not washed down by the rains and snows to decay on the moist soil, but stand firmly on the ground all winter long and “cure”, forming a quasi uncut hay. Thus the grass lands are of value both in summer and winter. In a broad way, the greater or lesser abundance of the grasses is dependent on latitude and altitude; the higher the latitude the better are the grasses, and they improve as the altitude increases. In very low altitudes and latitudes the grasses are so scant as to be of no value; here the true deserts are found. These conditions obtain in southern California, southern Nevada, southern Arizona, and southern New Mexico, where broad reaches of land are naked of vegetation, but in ascending to the higher lands the grass steadily improves. Northward the deserts soon disappear, and the grass becomes more and more luxuriant to our northern boundary. In addition to the desert lands mentioned, other large deductions must be made from the area of the pasturage lands. There are many districts in which the “country rock” is composed of incoherent sands and clays; sometimes sediments of ancient Tertiary lakes; elsewhere sediments of more ancient Cretaceous seas. In these districts perennial or intermittent streams have carved deep waterways, and the steep hills are ever washed naked by fierce but infrequent storms, as the incoherent rocks are unable to withstand the beating of the rain. These districts are known as the mauvaises terres or bad lands of the Rocky Mountain Region. In other areas the streams have carved labyrinths of deep gorges and the waters flow at great depths below the general surface. The lands between the streams are beset with towering cliffs, and the landscape is an expanse of naked rock. These are the alcove lands and cañon lands of the Rocky Mountain Region. Still other districts have been the theater of late volcanic activity, and broad sheets of naked lava are found; cinder cones are frequent, and scoria and ashes are scattered over the land. These are the lava-beds of the Rocky Mountain Region. In yet other districts, low broken mountains are found with rugged spurs and craggy crests. Grasses and chaparral grow among the rocks, but such mountains are of little value for pasturage purposes.

After making all the deductions, there yet remain vast areas of valuable pasturage land bearing nutritious but scanty grass. The lands along the creeks and rivers have been relegated to that class which has been described as irrigable, hence the lands under consideration are away from the permanent streams. No rivers sweep over them and no creeks meander among their hills.

Though living water is not abundant, the country is partially supplied by scattered springs, that often feed little brooks whose waters never join the great rivers on their way to the sea, being able to run but a short distance from their fountains, when they spread among the sands to be reëvaporated. These isolated springs and brooks will in many cases furnish the water necessary for the herds that feed on the grasses. When springs are not found wells may be sometimes dug, and where both springs and wells fail reservoirs may be constructed. Wherever grass grows water may be found or saved from the rains in sufficient quantities for all the herds that can live on the pasturage.

PASTURAGE FARMS NEED SMALL TRACTS OF IRRIGABLE LAND.

The men engaged in stock raising need small areas of irrigable lands for gardens and fields where agricultural products can be raised for their own consumption, and where a store of grain and hay may be raised for their herds when pressed by the severe storms by which the country is sometimes visited. In many places the lone springs and streams are sufficient for these purposes. Another and larger source of water for the fertilization of the gardens and fields of the pasturage farms is found in the smaller branches and upper ramifications of the larger irrigating streams. These brooks can be used to better advantage for the pasturage farms as a supply of water for stock gardens and small fields than for farms where agriculture by irrigation is the only industry. The springs and brooks of the permanent drainage can be employed in making farms attractive and profitable where large herds may be raised in many great districts throughout the Rocky Mountain Region.

The conditions under which these pasturage lands can be employed are worthy of consideration.

THE FARM UNIT FOR PASTURAGE LANDS.

The grass is so scanty that the herdsman must have a large area for the support of his stock. In general a quarter section of land alone is of no value to him; the pasturage it affords is entirely inadequate to the wants of a herd that the poorest man needs for his support.

Four square miles may be considered as the minimum amount necessary for a pasturage farm, and a still greater amount is necessary for the larger part of the lands; that is, pasturage farms, to be of any practicable value, must be of at least 2,560 acres, and in many districts they must be much larger.[1]