$Unique_ID{COW03827} $Pretitle{297} $Title{Uruguay Chapter 2. Physical Environment} $Subtitle{} $Author{The Director Foreign Area Studies} $Affiliation{HQ, Department of the Army} $Subject{rio country uruguay miles de la plata atlantic argentina montevideo} $Date{1971} $Log{} Country: Uruguay Book: Area Handbook for Uruguay Author: The Director Foreign Area Studies Affiliation: HQ, Department of the Army Date: 1971 Chapter 2. Physical Environment With an area of 72,172 square miles, the country is the smallest in South America. With the exception of Canada, it is the only country in the Western Hemisphere located entirely outside the tropics. Excluding Newfoundland, all of its land surface lies to the east of the North American continent, and the capital city of Montevideo is about 600 miles east of Bermuda. Its time zone is two hours earlier than Eastern Standard Time. The perimeter of the wedge-shaped country, often described as compact and homogeneous, is devoid of pronounced extrusions or intrusions (see fig. 1). The low plateau of the interior is marked by gentle up-and-down features except in the northeast, where the eroded hill ranges have sharp edges. The coastal lowlands have gently uneven characteristics featured by rivers and streams, sand dunes, small hill systems, and isolated knolls. Compactness of the country and the lack of high relief features have combined to make easier the construction of a good transportation network, in which all major roads and railroads originate along the frontiers and converge on Montevideo. This convergence is at once a cause and a consequence of the development of a settlement pattern that has resulted in the accumulation of almost half the population in the capital city, a concentration unrivaled in the Western Hemisphere. In addition, population density decreases in proportion to the distance from Montevideo, and the principal cities of the interior center are located along access routes leading to Montevideo. A transitional geological buffer between the landmasses of Argentina and Brazil, abundantly watered Uruguay is in a technical sense almost an island. Nearly all of its eastern perimeter is marked by a large tidal lagoon on the north and by the Atlantic Ocean. The southern coast is bordered by the great Rio de la Plata estuary, and on the west the country is separated from the northern part of Argentina by the Rio Uruguay. About two-thirds of the northern border corresponds to the course of major and minor rivers. Some border questions between Uruguay and its two contiguous neighbors, Argentina and Brazil, remain unsettled. None, however, represents serious problems and irredentism is not an issue. About 70 percent of the country lies in the La Plata drainage basin, an enormous area drained by the Uruguay and Parana river systems. Development of the waterpower resources of this region is an important projected program in which Uruguay, Brazil, Argentina. Paraguay, and Bolivia are to participate. Most of the countryside is made up of wide expanses of undulating prairie, an extension of the humid pampa of Argentina, broken in places by low ranges of hills pointing southwestward from the highlands of southern Brazil. Narrow lowlands of the Rio de la Plata littoral and the Rio Uruguay flood plain are devoted primarily to farming. The remainder of the country is a low, broken plateau divided into cattle and sheep ranches. About 90 percent of the territory is devoted to agricultural and pastoral undertakings. The topsoil is generally thin, but 70 percent of the land is considered tillable. There is little known mineral wealth except for iron deposits discovered in the 1960s, which have not yet been developed (see ch. 19, Industry). The relatively rugged northwest is the only subtropical part of the country. The remainder enjoys a moderate and pleasant temperate-zone climate marred only by winter fogs and occasional high winds. It is, however, an uncertain climate marked from time to time by droughts and floods. Because plateau and plain are broken up by barbed-wired fences dividing them into ranches and farms, it is only in the northwest that a few of the larger indigenous animal species survive. Wildfowl are numerous in the lagoons and marshes of the Atlantic coast, however, and game and other bird species abound on the plateaus and along the southern coast. The generally excellent deep-sea and surf fishing are at their best in the vicinity of Punta del Este. The rural settlement pattern corresponds to regional differences; farms occupy the coastal lowland, and cattle and sheep ranches are found on the interior plateau. In general, population density is the greatest near Montevideo, the one great urban center, and least in parts of the country remote from the capital. Natural Featrues Topography The country represents a transition from the pampas of Argentina to the hilly uplands and valley intersections of southern Brazil's Parana plateau. In general, it is a country of gentle hills and hollows. This rolling characteristic is general but less evident close to the eastern, southern, and western borders. In the northeast corner, adjacent to Laguna Merin, is a low plain area where rice is grown under irrigation. Directly southward, a narrow alluvial Atlantic coastal plain is broken by sand dunes, marshes, and coastal lagoons. Infertile stretches of sandy soil extend inland for distances of up to five miles. At Punta del Este, the coastline leaves the Atlantic to veer westward sharply for more than 200 miles along the Rio de la Plata estuary to the mouth of the Rio Uruguay, the estuary's westernmost extremity. The littoral is somewhat broader here and merges almost imperceptibly with the grasslands and hills of the interior. Soils consist of sands, clays, loess, and alluvium deposited by the numerous streams. The black soil is rich in potassium and enriched by decay of the lush cover of vegetation. Soils of similar composition are found on the flood plain of the Rio Uruguay, which forms the country's western frontier. Along this flood plain,however, in the portion to the north of the mouth of the Rio Negro there are extensions of the interior hill ranges that encroach on the flood plain. The remaining three-fourths or more of the country consists of a rolling plateau, featured by ranges of low hills that become more prominent in the north as they merge into the highlands of southern Brazil. The geological foundation of most of the region is made up of gneiss, red sandstone, and granite, and an extension of the basaltic plateau of Brazil reaches southward in a broad band west of the Rio Negro. Corridors between the hill ranges are floored with clay and sedimentary deposits. Legend holds that when the ship of the discoverer Magellan first made landfall in the Rio de la Plata, on sighting the conical hill west of the site of what was to become Montevideo, his lookout called out in Portuguese "Monte vide eu" (I see a mountain). This quite possibly is how the capital city acquired its name, but the country as a whole is so lacking in lofty relief features that its highest peak is Cerro Mirador in Maldonado Department near the southern coast. Its height is 1,644 feet. The most important of the cuchillas (hill ranges) are the Cuchilla Grande and the Cuchilla de Haedo. Only in these and in the Cuchilla Santa Ana along the Brazilian frontier do altitudes with any frequency exceed 600 feet. Both of the two major ranges extend southwestward from Brazil, one on the eastern flank and one on the western, in directions roughly defining the course of the country's principal river, the Rio Negro. To the east, the Cuchilla Grande and its several spur ranges form the country's most extensive hill system and its most important drainage divide. Here, ridges are frequently 1,000 feet or more in elevation. West of the river in the northern portion of the Cuchilla de Haedo, near the Brazilian border, is the site of the Uruguayan countryside's most nearly rugged terrain. Elevations are low, but eroded layers of sandstone and laval deposits sometimes overlaid by basalt give sharp outlines to the topography. The rolling character of the land surface derives from the presence of dozens of these cuchilla ranges. Insignificant as relief features, they have been important factors in the development of the country . In many instances the ridges serve as administrative boundaries and as the routes followed by the roads and railroads, which frequently tend to avoid the underbrush-clogged lowlands along the rivers and streams. In addition, they contribute to a drainage system much more effective than that of the Argentine pampas, where the uncompromising flatness of the land prevents much runoff after rains and causes surface water to accumulate. Hydrography The name of Uruguay, first applied to the Rio Uruguay, may have been taken from the Guarani Indian word urugua, meaning a kind of mussel. Another explanation is that it derives from Guarani word-components meaning birds that come from the water. Both are indicative of a well-watered land. Most of the country's frontiers are riverine; rivers, streams, and occasional watercourses form an elaborate tracery over the entire country; lakes and lagoons are numerous; and a generally high water table makes well-digging easy. The largest of the rivers is the Rio Uruguay, but the country can claim only partial title to it. The river marks the entire western boundary with Argentina and extends farther to the north as a portion of the Argentina-Brazil frontier. It is flanked by low banks, and disastrous floods sometimes inundate large areas. The Rio de la plata, marking the entire southern boundary, is actually an estuary of the Atlantic Ocean and is saline except at its western extremity, where the Parana and the Uruguay spew enormous quantities of fresh water into it. There are three systems of internal rivers and streams: those flowing westward into the Rio Uruguay, those flowing eastward either into the Atlantic Ocean or into tidal lagoons, and those flowing southward into the Rio de la Plata. Most of the rivers draining westward originate in the inland hills and descend through narrow valleys to join the Rio Uruguay. The longest and most important, however, is the Rio Negro, which rises in southern Brazil. It bisects the country as it flows southwestward over a distance of some 500 miles to join the Rio Uruguay south of the town of Fray Bentos. Its principal tributary, and the country's second most important river, is the Rio Yi, which flows a distance of 140 miles from its source in the Cuchilla Grande. Other major western rivers originate in the Cuchilla de Haedo and join the Rio Uruguay north of Paysandu. The rivers flowing eastward originate in the Cuchilla Grande and are shallower and more variable in flow. They empty into lagoons, located behind the coastal dunes, or directly into the Atlantic through small estuaries. The largest of these, the Rio Cebollati, flows into Laguna Merin. The irregularity of the country's drainage pattern is illustrated by the fact that the headwaters of this eastward-draining river lie some fifty miles to the west of that of the westward-draining Rio Yi. In 1937 work began on a Rio Negro dam at a site a short distance upstream from the town of Paso de los Toros in the central part of the country. The resulting reservoir, called the Embalse del Rio Negro, with a length of 87 miles and surface area of over 4,000 square miles, is the largest manmade lake in South America. At a later date a second dam was constructed on the river a few miles downstream from the first. The two dams are sites of major hydroelectric power installations. The largest of the eastern coastal lagoons is the Laguna Merin. Serving as a part of the northeastern frontier with Brazil and with its northern extremity located entirely in Brazil, it discharges its waters through that country's Sao Goncalo Canal. Strung along the coast between the Brazilian border of Punta del Este are a half-dozen other lagoons with surface areas of fifteen to seventy square miles as well as numerous smaller ones. Some are fresh water, while others have direct tidal connection with the Atlantic and as a consequence are brackish. Some 775 miles of the country's rivers are reported to be navigable. This figure, however, apparently includes 235 miles along the Rio de la Plata estuary. On the Rio Uruguay oceangoing vessels of up to fourteen feet in draft can ascend 140 miles to Paysandu, and vessels with drafts of up to nine feet can continue 60 miles farther to Salto, where passage is blocked by falls. Much of the Rio Negro is obstructed by sandbanks and shallows, but it is navigable by coastal vessels for about 45 miles upstream from its mouth. Rivers navigable for some distance by shallow-draft small craft include the Yi and Quequay Grande in the west, the Cebollati in the east, and the Santa Lucia in the south. Geographical Regions The land is homogeneous, and changes in topography, climate, and vegetation are limited in character and moderate in degree. The two principal regions of the country are the Agricultural Lowland and the Pastoral Plateau Interior. The agricultural Lowland starts in Maldonado Department and follows the littoral of the Rio de la Plata westward for the full extent of the estuary in a band averaging about fifty miles in depth. It is sometimes regarded as continuing northward along the Rio Uruguay in a narrowing band as far as the river town of Salto. Rarely, the sand dunes and swamps of the Atlantic plain are also included. Soil, relief, and vegetation vary considerably within the Agricultural Lowland, which merges gradually with the rolling grasslands of the interior, but it is an area of varied and intensive agriculture in which most of the population lives. The Pastoral Plateau Interior makes up the remaining three-fourths or more of the country. In general, sheep ranches occupy the territory to the north of the Rio Negro, and cattle ranches prevail to the river's south. Mineral Resources The country's deficiency in minerals has limited the development of industry. With the exception of a fairly large deposit of 40 percent iron ore that has been located in the central part of the country, the search for metallic minerals has been generally unavailing. In early 1970, however, plans were reported for development of ilmenitic beach sands along the coast between Montevideo and Aguas Dulces on the Atlantic as a source of rutile, zircon, and monazite. Manganese, copper, lead, and gold discoveries do not appear to be in commercially useful concentrations, and initial offers of offshore leases for petroleum prospecting have failed to arouse much interest. Building materials located in the south-central part of the country make up most of the nonmetallic minerals production. Good quality marble, granite, talc, limestone, building stone, and sand are produced for domestic use and sometimes for export. Semiprecious stones, such as opal, agate and onyx, are found in limited quantities in Salto and Artigas departments. Under Uruguayan law all products of the subsoil are the product of the state. Vegetation Most of the country is grassland, some of the native prairie grasses similar to those of the Argentine pampas having been replaced by planted varieties with higher yields value. In the spring these grasslands are interlaced with wildflowers, including the verbena, which is said to have caused the Anglo-Argentine writer W. H. Hudson to give the title The Purple Land to a nineteenth-century book. Vegetation in general is temperate except in the northwest, where forests are thick, trees are dressed with creepers, and orchids grow. Less than 3 percent of the country is forested. Most of the native forest occurs in bottom lands of watercourses, particularly in the northeast, where stretches of mixed forest and woodland in the valleys link the region to corresponding natural features in southern Brazil. Among the hardwoods are algarrobo, quebracho, urunday, and guayabo. Other forest species include the scarlet-flowered ceiba, acacia, alder, willow, myrtle, mimosa, rosemary, and aloe. Vines and underbrush are sometimes heavy, and medicinal herbs native to these woodlands include sarsaparilla, camomile, and quinine. The rocky slopes of the low hills are frequently covered with bracken. The only trees indigenous to the grassy plateaus are the palm and the ombu, a long-lived growth that is more herb than tree. The pulpy wood of the ombu does not have much use, even as fuel, but the growth achieves considerable height and interrupts the monotony of the wide stretches of grassland while providing welcome shade to cowboys and cattle. Planted stands of palm are found along the Atlantic coastline where, together with plantations of maritime pine and eucalyptus, they were set out to half the inward drift of the beach dunes. These trees and poplars are often found along roads and surrounding houses in all parts of the country. Wildlife The larger indigenous animals have virtually disappeared, except in the broken terrain of the semitropical northwest. Among the species still sometimes seen are the rhea (or American ostrich), nutria, small deer, puma, jaguar, wildcat, fox, anteater, and several kinds of small rodent. Seals swarm over the rocky Lobos Island at the mouth of the Rio de la Plata near Punta del Este. In 1970, however, more than 90 percent of the national territory was being used economically, and barbed-wire fences striated the rangeland. There was little remaining room in which wild animals could roam. Salt-water fish abound in three fishing zones. These are the low zone, which extends from Colonia, across the Rio de la Plata from Buenos Aires, eastward to Piriapolis; the middle zone, one of the world's finest game-fishing sectors and a prime locality for commercial fishing, from Piriapolis to Punta del Este, some twenty-five miles to the east; and the high zone, from Punta del Este along the Atlantic coastline to the Brazilian border. Among the principal species are the corvina negra (black bass), mackerel, tuna, merluza (hake), mullet, sole, whiting, and anchovy. Weakfish, drumfish, and bluefish are the most sought-after surf-casting catch off Punta del Este. The best known of the fresh-water species is the golden-yellow dorado, a kind of salmon or trout. The Atlantic coastal swamps and lagoons teem with waterfowl, including the flamingo, swan, crane, and white heron. On the plateau and along the Rio de la Plata littoral are found the partridge, quail, native crow, vulture, lapwing, hummingbird, cardinal, and a tiny burrowing owl. The hornero (oven-bird) builds its oven-shaped nest on fenceposts and telegraph poles in all parts of the country, and parakeets and other tropical birds are sometimes encountered in the semitropical northwestern uplands. The reptiles include a dangerous viper called the vibora de la cruz, rattlesnakes, lizards, and tortoises. An occasional alligator is seen along the shores of the Rio Uruguay. Venomous spiders are fairly common, and locust swarms appear periodically in portions of the interior plateau. Climate The small size and even physical characteristics of the country limit the extent of regional variations in climate, although the generally temperate weather conditions are replaced by the almost tropical in the northwest, where they are similar to those prevailing in northern Argentina and Paraguay. The absence of high relief features to act as weather barriers makes it especially susceptible to climatic variations caused by external influences, particularly in coastal lowlands. These variations are caused by the downward movement of air masses from the Brazilian highlands; anticyclones originating in the south Atlantic; and periodically, winds blowing northward from the Argentine pampas. In all parts of Uruguay except the northwest, spring is usually damp, cool, and windy; summers are warm; autumns are mild; and winter cold is made uncomfortable by dampness, although frost and freezing temperatures are virtually unknown. About half of the days of the year are usually sunny, but fogs are common from May to October, especially near the coasts. It is also during this part of the year that drops in temperature between midday and the hours of darkness are most pronounced. As reported by six widely scattered meteorological stations over a thirteen-year period, mean annual temperatures ranged from 67.7F. at Punta del Este on the southern coasts to 67.7F. at Artigas in the northwest. Seasonal variations were limited. The lowest average during a month in Punta del Este was 51.6F. in July, and the highest was 70.5F. in January. In Artigas the lowest was 55.8F. in July, and the highest was 79.7F. in January. The mean annual rainfall is about 42 inches, rainfall decreasing in direct proportion to distance from the coasts. Winter rains are the most frequent, but autumn rains are the heaviest. There is no definite dry season. Rainfall tends to be lowest in summer, but summer thunderstorms are frequent. Regionally, rainfall during the thirteen-year period ranged from an average of 35.35 inches in Punta del Este to 49.25 inches in Artigas. High winds are a disagreeable characteristic of the weather, particularly during the winter and spring, and wind shifts are pronounced. The hot zonda, blowing out of the north, may be replaced by an occasional violent and chilly pampero during the winter months. Resulting from the meeting of cool winds blowing northward over Argentina with warm air masses moving southward, the pampero causes massive backing up of waters of the Rio de la Plata and rains accompanied by sudden drops in temperature over Uruguay. A localized windy phenomenon is the tormenta, a sudden convectional activity accompanied by thundershowers. The various winter and spring winds have the salutory effect of keeping the atmosphere fresh despite the prevailing humidity, and the easterly maritime winds of the summer season temper the hot temperatures of midday. Despite the absence of extreme seasonal changes in weather conditions, day-to-day changes are considerable. In the coastal lowlands these are moderated somewhat by proximity to the Atlantic or the Rio de la Plata. On the interior plateau, however, they can reach uncomfortable extremes such as those that occurred during 1967. The year was marked by a lengthy drought resulting in the drying up of waterholes and streams, which occasioned the loss of a considerable number of livestock. The ending of the drought was accompanied by unusually cold weather and torrential rains, particularly in the north, where the drought had been at its worst. Swollen streams overflowed their banks and spread over the pastures to cause the death by starvation or drowning of many more cattle or sheep. It was the worst year in terms of weather since 1959, and the arbitrary measure of eight good years between two bad ones is as good as any for measuring the irregularity of the generally pleasant but unpredictable climate. Boundaries and Political Subdivisions The country is bounded on the north and northeast by Brazil and on the south and west by Argentina. The southeast portion of the perimeter is on the Atlantic Ocean. Boundaries correspond generally with natural features, a majority of them riverine and other water features. From a point on the Atlantic seaboard just above the 34th parallel, the Brazilian frontier extends northward along the course of minor streams and the principal channel of the Laguna Merin to about the 33d parallel, where it continues northwestward to the tripoint with Brazil and Argentina on the Rio Uruguay. Rivers mark most of this section of boundary, although its middle one-third follows the ridges of a range of hills and an arbitrary straight line. Although the full extent of the Brazilian boundary has been demarcated, in 1970 there was still some question about the true source of one of the boundary rivers and about sovereignty over a small river island. From the tripoint on the Rio Uruguay, the boundary with Argentina extends directly southward along the course of that river and is delineated for its full extent of about 340 miles to the Rio de la Plata. With ratification in 1965 of a 1961 treaty, title to most of the numerous islets dotting the river was agreed upon. In 1970, however, both countries continued to claim certain islands in the Rio de la Plata near the river's mouth below the town of Punta Gorda. The most important was Martin Garcia, administered by Argentina and the traditional detention place for its political prisoners. In 1961 the governments of Uruguay and Argentina issued a joint declaration defining the outer limits of the Rio de la Plata estuary as a line running southwestward from Punta del Este in Uruguay to Cabo San Antonio in Argentina. For most of its length, however, the Rio de la Plata is more than thirty miles in width, a principally salt-water estuary of the Atlantic Ocean. Although Uruguay has stated that it is a true river, certain other nations have held that it is an international waterway. The 1961 compact did not include agreement as to where in the estuary the border between the two countries should be drawn. Uruguay has generally held that the border should be the median line between the two coasts, whereas Argentina has claimed that it should follow the deepest channel, a course that for the most part lies relatively close to the Uruguayan shoreline. In addition, there has been some disagreement over the location of the median line itself. In 1969 conversations aimed at reaching agreement with respect to the location of the boundary in the estuary were initiated. Another significant event of late 1969 relating to sovereignty over the waters of the estuary was the Uruguayan government's issuance of a decree proclaiming sovereignty over all territorial waters to a distance of 200 nautical miles from the shoreline for purposes of fishing and exploitation of the resources of the ocean floor. Earlier in the same year, the distance had been extended from 6 to 12 nautical miles. The decree extending the claim to 200 miles included the statement that there would be no interference with the innocent passage of air and surface craft over the water at distances between 12 and 200 miles, but that fishing in this zone by foreign flag vessels would require prior authorization by the executive branch. The principal political subdivisions of the country are its departments. With the exception of the department of Montevideo, which occupies only 0.3 percent of the national territory, they range in size from Canelones, with 2.6 percent, to Tacuarembo, with 9.0 percent. Departmental boundaries for the most part correspond to natural features. The courses of rivers and streams are the most frequently used, the Rio Negro alone bordering on seven departments. The ridges of the innumerable cuchillas are also frequently used, and in some instances borders correspond to old property lines. There are no important straight-line sections of internal borders. The country as a whole is so compact, however, that political subdivisions cannot be said to correspond to geographical regions or ethnic settlement patterns. The nine blue and white horizontal stripes of the national flag represent the number of departments in existence in 1830, the time at which the flag was adopted. By 1970 the number had increased to nineteen by means of an evolutionary process in which towns grew in size and importance and extended their influence into the surrounding countryside. The capital is invariably the most important urban center in the department, and in thirteen instances departments bear the name of their capitals. They do not significantly affect political and socioeconomic patterns. There are some differences within the country, but these tend to be regional or urban-rural rather than departmental (see ch. 4, Population and Labor Force; ch. 5, Ethnic Groups and Languages; ch. 16, Political Values and Attitudes). Settlement Patterns Although no city in Uruguay other than Montevideo has a population much in excess of 60,000, the country is the most urbanized in South America, for about half of the country's people live in the capital city. The continuing nature of the shift in concentration of population is suggested by the circumstances that the 1963 census found 46.3 percent of the people living there and that a 1967 estimate raised the proportion to 49 percent. For 1970 an estimate of 50 percent seems moderate. In no country of the world is population so concentrated in a capital city except in city states such as Luxembourg and Singapore (see ch. 4, Population and Labor Force). The importance of Montevideo as a settlement lodestone is further emphasized by a glance at the density of population in the rest of the country. In the capital city and in the remainder of the department of Montevideo and the neighboring department of Canelones, the population density in 1963 averaged 980 per square mile. In the remainder of the southern lowlands it was 22 per square mile, and in the interior plateau region it was 13. Within the plateau interior itself, that part south of the Rio Negro was more heavily populated than that to the river's north. The only exception to the general pattern of settlement growing progressively sparser in direct proportion to the linear distance from Montevideo occurs in the Rio Uruguay flood plain, where intensive agricultural and pastoral activities are practiced and the largest individual urban concentrations outside of the capital city are found. The other major urban centers are the department capitals and these, without exception, are located on major transportation routes converging from the frontiers toward Montevideo. To the west and south, the Rio Uruguay and the Rio de la Plata estuary connect Montevideo with the waterside departmental capitals of Salto, Paysandu, Fray Bentos, Mercedes (via the navigable lower reaches of the Rio Negro), and Colonia. Each of these centers also has direct highway access to the national capital. The north-south highway route from Rivera on the Brazilian frontier passes through the capitals of Tacuarembo, Durazno, Florida, and Canelones. Farther eastward, the Pan American Highway system links Melo, Treinta y Tres, and Minas. The remaining five departmental capitals also lie on highways linking Montevideo and the frontier (see ch. 21, Trade). Smaller towns of the interior also have tended to develop along access routes to Montevideo. Lateral routes crossing the country from east to west are remarkably few, but as a general rule market towns are found at crossroads. Farm villages are not characteristic of the countryside, and small individual farms are numerous in the south. During the late 1960s, however, over half the national territory was in pastoral or agricultural estates of more than 2,000 acres, and about seventy of the estates had more than 25,000 acres. In some of the large properties, workers lived in large clusters having the characteristics of towns, but a more frequent pattern was the scattering of a few dwellings in the immediate work areas. In addition, there were the rancherios (collections of up to 200 rural slum shanties strung out along watercourses or roads) housing itinerant workers during off seasons and the families of regular ranch or farm hands who were not ordinarily permitted to live with their family heads on the worksite. Estimates with respect to number of people living in rancherios varied considerably, but the total may have been as much as one-fifth of the rural population (see ch. 7, Living Conditions).