Master Plan
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The proposed Amistad National Recreation Area will be a spacious and scenic unit of land and water with a high carrying capacity for diversified water-based outdoor recreation. Basic reservoir operating commitments of the Amistad Project, though marked by rather wide, irregular fluctuations in the water level which will occasionally limit public use, will be compatible with fulfillment of its recreation mission. Its recreation opportunities are of a significance to assure both interstate and international patronage, and the total demand for use of the resources will be heavy. The investment and operational responsibility required to develop these resources on a scale commensurate with their public-benefit potential are so high as to indicate substantial Federal involvement.

Accessory resource values at Amistad will contribute materially to visitor enjoyment of its primary recreation qualities. In itself, the area's natural history is neither unique nor of great significance, but contains enough variety and interest to appreciably enhance the recreation benefits. Also, the historic chapter of man's presence in the area is of no more than regional interest, but it offers a definite bonus for the visitor who takes the time to savor it. It is the area's prehistory which constitutes the outstanding secondary resource.

Its significance is well summarized by Graham and Davis (see Appendix):

In several respects the Diablo [Amistad] Reservoir is one of the unique archeological regions of North America. Probably no area of comparable size can boast of so rich a series of archeological and pictographic sites. In the desiccated rockshelters, in the open midden sites, and in the stratified terrace sites are preserved an unusually complete array of material remains, representing, all in all, several thousand years of human history and prehistory. For this reason alone the archeology of the area is of exceptional scientific significance. But in addition to this rich inventory . . . here exists one of the truly unique pictograph regions of the world. The magnificent galleries of superb cave murals . . . are perhaps comparable only to the famous cave paintings of Europe.

Amistad Reservoir will both destroy parts of this resource and render others more accessible for public enjoyment. Most of the great rockshelters and pictographic sites will be above maximum water level. The particular culture and the unique style of rock art represented here are not receiving protection elsewhere.

South across bends of Rio Grande in mid-section of reservoir, Mexico in distance. Comstock recreation site borders river in center foreground.



Amistad Reservoir's recreation resources will be substantial. It will be an impressively large body of water in an attractive setting. At its maximum operating-pool elevation of 1,117 feet above sea level, the lake will extend some 74 miles up the Rio Grande, approximately 25 miles up the Devils River, and about 14 miles up the Pecos. At this level the water surface will have an area of 67,000 acres, 43,250 of them in the United States. There will be 851 shoreline miles, 547 of them in this country. During the brief periods of flood storage these dimensions will be considerably greater. Reservoir operating requirements will result in a cyclic heavy drawdown, but even at levels well below 1,117 feet the lake will be large enough to provide for a full range of boating, sailing, fishing, and other water sports activities.

Because of erratic rainfall and streamflow in the drainage basin, and of the necessity to operate the reservoir in conjunction with Falcon Reservoir requirements downstream, it is anticipated that water-level fluctuation at Amistad will not be directly seasonal. The accompanying chart depicts what the probable continuous variation would have been if Amistad Dam had existed during the period from 1900 to 1956, based upon known streamflow data and projected future release schedules. Predictions of the actual pattern following closure of the dam can do no better than assume a repetition of this same cycle, but not necessarily from the same point of beginning. In this regard, it should be noted that both 1901 and 1904 were drought years in Texas, and the protracted initial storage buildup on the chart should not be considered representative. Under the vagaries of precipitation in this watershed from year to year, the reservoir's initial filling may as likely be spectacularly rapid as disappointingly slow. What the chart does indicate is that, while the reservoir surface will remain close to the operating elevation of 1,117 feet for years at a time, there will also be periods of several months' or years' duration when water levels will be consistently well below it. Water will not stand higher than 1,117 feet for long, since storage capacity above that elevation is allocated to flood control, and increment water will be released as rapidly as feasible to restore the operating-pool level.

Down Rio Grande to damsite (between first and second bends) before construction. Lower Rio Grande recreation site is on left bank beyond. Devils River entering from left, Mexico on right.

It is during the occasional deep drawdowns that recreational use of the reservoir will be adversely affected and its attractiveness diminished. There will always be a sizable body of water, for even at the maximum drawdown of 130 feet below operating level the impoundment will extend up the Rio Grande about 28 miles, and water will be 90 feet deep at the dam. However, it is not feasible to extend boat ramps all the way down to this limit, and there will be periods when lake launching from the larger development sites will simply be suspended. Concession operations will be marginal there during these times, which may be as much as 2 years in duration, though not aggregating more than 4 percent of the overall cycle. It will still be possible then to launch boats into the flowing river at the proposed Langtry, Pecos River, and Lower Rio Grande sites, and the old U.S. Highway 90 at the Devils River Crossing will serve as a temporary ramp access to the main part of the reservoir. The Rough Canyon site will never be put out of business because of the guaranteed presence of water in the former Devils Lake.

Under prevailing conditions the main body of the reservoir will be a pool with a highly indented shoreline and an irregular shape with broad expanses of water. There will be an endless variety of bays and coves, some long and narrow, others with widths of several miles. Water vistas of 7 to 12 miles in a given direction will he common, and in the large basin centering on the Rio Grande-Devils River confluence there will be an almost uninterrupted reach of water over 20 miles across at highest operating level. Numerous islands will be formed at all water levels. Sharply contrasting with this part of the reservoir will be its upstream sectors along the three rivers. Here, the maximum lake level will remain below the rims of the sheer canyon walls; a totally different scenic experience will be provided in these narrow cliff-lined corridors. Within the recreation area boundaries there will almost always be stretches of free-flowing river in these canyons upstream from wherever the slack-water level of the impoundment is located at the time.

As in any reservoir, sedimentation will occur in the upper canyon reaches. It will be most pronounced on the Rio Grande because of its heavier silt load, moderate on the Pecos River, and only slight on the spring-fed Devils River. Each time the reservoir level drops from a temporary high, the Rio Grande, in particular, will expose fresh silt banks as it flushes the deposit farther downstream. These banks will inevitably impair scenic qualities in the uppermost parts of the canyon and will require some maintenance to keep a boat-launching ramp at Langtry in operation.

The river released below Amistad Dam will be a cold, clear stream with a minimum flow of about 1,000 cubic feet per second. A two-mile stretch of the riverbank here will be included in the recreation area for public fishing access.

Lands bordering the reservoir are generally quite suitable for facilities and access to water-oriented activities and for associated land recreation, including camping, picnicking, shoreline exploration, hiking, nature study, photography, and hunting. Other than in the upper canyon reaches and the major development sites, most lands to be acquired at Amistad are below the 1144.3-foot contour and theoretically subject to flooding. However, the operational studies indicate this condition will virtually never be fully reached and most of the time the reservoir level will be such that a strip of land varying in width from a few hundred feet to a mile or more will exist between the lake and the recreation area boundaries. The upper canyons will always have scenic areas above water. The many islands that will exist at various reservoir levels will lend themselves well to recreational use by boating parties.

Comparative characteristics of Amistd Reservoir at four selected water levels. (click on image for an enlargement in a new window)


Geology: For many miles of its course along the international boundary between Mexico and the United States, the Rio Grande flows through a vast area of desert plains and rugged mountains. Shortly after leaving the Big Bend country it swings to the east and enters the Edwards Plateau section of the Great Plains province. Here the river is consistently entrenched in a canyon of its own carving, several hundred feet deep, walled by nearly level-lying Cretaceous limestones of the Comanchean series. The area's geologic structure is that of a slightly uplifted, mildly flexured and faulted peneplane. The surface of this rather young plateau has not yet been severely dissected; broad, gently rolling segments are cut abruptly by steep-walled tributaries of the major streams. Near its border with the West Gulf Coastal Plain, the surface of the Edwards Plateau becomes more rounded. The underlying Georgetown limestone still controls the character of the landscape, but less resistent Del Rio shales and younger gravels have eroded into a softer pattern of low hills and shallow open valleys. It is in this zone of physiographic transition, characterized by bluff-lined canyons punctuating a region of gentle relief, that Amistad Reservoir will be situated.

Biology: The Amistad Reservoir site is transitional between the Chihuahuan and Comanchian biotic provinces (according to Dice), or it lies at the common meeting point of the Chihuahuan, Balconian, and Tamaulipan provinces (according to Blair). The area is generally classified as chaparral country. Although the plants and animals are mostly those of the limestone uplands of the Edwards Plateau, there is an appreciable intermingling of species characteristic of the Chihuahuan Desert.

Because of the thin soils, limited rainfall, and long history of grazing use, the vegetative cover on the higher lands bordering the reservoir is sparse. The most obvious plants are catclaw, ocotillo, yucca, cenizo, lechuguilla, blackbrush, creosotebush, sotol, leatherplant, and various cactuses. Scattered low-growing trees such as mesquite, shin oak, live oak, Texas persimmon, and hackberry are found in protected locations. Prior to the introduction of cattle and, later, sheep and goats, short grasses formed a significant part of the vegetation, but now comprise only a small percentage of the flora. Along the narrow bands of deep, well-watered alluvium bordering the rivers the vegetation is lush and of a different nature. Here thick stands of cane and other tall grasses and dense growths of willow, mesquite, and tamarisk are typical. Although much of this type will be inundated, it will remain in the area below the dam and in the upper reaches of the reservoir where flooding will occur only for occasional short periods.

Interesting changes in vegetative composition can be expected along the fluctuating shoreline. In those areas not subject to flooding or grazing (recreational development sites and some of the more permanent islands which will be created), the original varied and highly interesting flora should become re-established.

The fauna is diverse. Mammals commonly found in the area are coyote, whitetail deer, collared peccary, ringtail, raccoon, skunk, jackrabbit, cottontail, rock squirrel, and several other rodents. Reptiles are represented by various snakes and lizards including the poisonous diamondback and rock rattlesnakes. Common birds are the vulture, raven, quail, mourning dove, white-winged dove, sparrows, wrens, and various types of water birds including the great blue heron and several ducks. Principal fish species are channel catfish, bass, bluegill, shiner, carp, gar, and crappie. Some unusual animals found or to be expected in the area include Mexican opossum, coati, ocelot, tropical indigo snake, south Texas ground snake, Texas alligator lizard, and golden-fronted woodpecker.

West across Seminole Canyon to huge Fate Bell Rockshelter, one of the most important and spectacular archeological sites in region.


The Amistad Project area is also a country replete with the romance and adventure of human history—of Indian cultures dating back to 8000 B.C. and of Spanish exploration, possibly as early as A.D. 1535 when Cabeza de Vaca must have passed through this country in his wanderings among the Indians. In the vicinity are some of the huge "working ranches" of Texas, punctuated by vestiges of the early West—ghost towns and military posts. Few episodes are more appealing to the imagination than the indomitable one-man rule of "Judge" Roy Bean, self-styled dispenser of justice at his storied "Law West of the Pecos" court at Langtry during the 1880's and 1890's. The era which spawned this colorful reign was an eventful time in the development of the West, when railroads were being built to span its vast distances and a firm hand was needed to deal with lawlessness in the brawling construction camps at the "end of the track." Several of these camps were located in the Amistad vicinity.

If the Amistad area possessed no other resource attributes, it would be of exceptional public interest and scientific significance by virtue of its archeological values. Over 300 known sites representing thousands of years of human occupation exist on the U.S. side of the reservoir basin alone. These are primarily concentrated along or near the major stream canyons and their tributaries, where water was available and ideal shelter was afforded by the many natural cavities and overhangs weathered out of the massive limestone bluffs. The largest and most spectacular of the rockshelters are mainly confined to the lower Pecos River and adjacent stretches of the Rio Grande (see Archeological Base Map). Some of these openings reach dimensions of over 500 feet broad and 200 feet deep, and ceilings are often as much as 50 feet above the floors. In a different class are numerous open surface sites located on stream terraces or on the tops of the bluffs, occasionally removed some distance from the streams. Some of the terrace sites are buried in alluvium and thus have a well-preserved stratigraphy.

Black Cave, a large rockshelter in Big Canyon, eastern tributary of Seminole Canyon.

Cultural deposits in the extensive midden heaps—many of them deep and clearly stratified—have yielded a wealth of information concerning prehistoric man's occupancy of the region. The confirmed time span is from the big-game hunters of at least 10,000 years ago in the Paleo-Indian Stage (prior to 7000 B.C.), through the Archaic Stage (7000 B.C. to A.D. 1000) and Post-Archaic Stage (A.D. 1000 to 1600), and into the early part of the Historic Stage (A.D. 1600 on). The best known culture unit of the Archaic Stage in southwest Texas is the Pecos River Focus. The enormous Fate Bell Rockshelter in Seminole Canyon in the proposed national recreation area has been designated as the type site for this focus.

Archeological Base Map. (click on image for an enlargement in a new window)

Although there appear to be no long breaks in the continuity, an intermittent occupation or use of the shelters and other sites in this region is suggested by the character of the remains, which lack the structural elements and tools normally associated with sedentary cultures. All are typical of a way of life dependent on a hunting and gathering subsistence adapted to an arid or semiarid environment.

Inside Fate Bell Rockshelter, designated as type site for Pecos River Focus of Archaic Stage. This will be of significant visitor interest and will require protection from vandalism.

Particular distinction is given this region by the extent and quality of its primitive rock art. There can be little doubt that the Amistad area is one of the major pictograph localities of the world. Panels of superbly executed pictographs, many in an excellent state of preservation, are found throughout the reservoir basin in association with the overhangs and large rockshelters along the rivers. The murals in the area around the Pecos-Rio Grande confluence combine color, form, and composition in a highly developed art style which probably has few parallels in the New World. The Amistad pictographs are also notable for their abundance in a relatively small geographic area. Some of the sites also contain petroglyphs—figures pecked in the rock surface.

Panther Cave or Rockshelter near mouth of Seminole Canyon, one of the most important pictograph sites. Painting of panther is on far wall between two visitors. Site will require protection because of easy access from reservoir.

Pictographs in Panther Cave.

The vast majority of the paintings feature a polychromatic technique and depict highly stylized life-size anthropomorphic figures, naturalistic animal representations, and a variety of geometric forms. Artistic qualities of color harmony and balance, accuracy, conventionalization, and action are remarkably advanced. This style appears to be related to the Pecos River Focus and is the dominant tradition of the Amistad area. Another style which is regarded as a late intrusion is found either in separate sites or superimposed upon the earlier Pecos River Focus art. Its paintings are in red or black monochrome and are characterized by realism in the depiction of natural forms. At one site in the proposed national recreation area, pictographs of this later type include historical elements such as horses, missions, and men in European dress.

Another archeologic feature at Amistad is both fascinating and unique. At Bonfire Shelter in Mile Canyon is a bison-kill site that was used repeatedly by Paleo-Indian hunters and, after a lapse of more than 7,000 years, briefly by Indians of late Archaic times (about 650 B.C.). The site was a bison "jump"—a precipice over which the Indians drove herds of unsuspecting bison to their death and then butchered them. Although the technique was fairly standard in the northwestern Plains, no other such kill site is known within 350 miles of this solitary one at Amistad. Recent studies of this jump indicate that during its second brief period of use—perhaps lasting only one season—over 800 bison were herded over the lethal cliff in a single, extremely successful drive.

Across Mile Canyon to site of Bonfire Rockshelter and bison jump. Prehistoric Indians killed bison by driving them over cliff just beyond talus slope and butchered them in cave behind talus. Site was inhabited intermittently for over 10,000 years.

Investigations of Amistad's archeological resources began with a limited reconnaissance by the Witte Memorial Museum and the Southwest Texas Archeological Society in the early-1930's and continued sporadically in that decade with exploratory studies and excavations of a few selected sites. The University of Texas, Gila Pueblo, the Smithsonian Institution, and the West Texas Museum were among the sponsors of these early investigations. Their findings were never adequately published but they did serve to focus attention on the richness of the region's archeological remains. In so doing, they also touched off an era of vandalism and looting which has left few of these sites undisturbed.

General site and pictograph surveys were also conducted in the 1930's by several individuals, notably Forrest Kirkland for the Texas Archeological and Paleontological Society and A. T. Jackson for the University of Texas. J. Charles Kelley carried out extensive research on the archeology of Trans-Pecos for the West Texas Historical and Scientific Society during this period and he is largely responsible for the present archeological concepts of the region. These studies are well reported in the literature.

In the 1950's, with approaching realization of plans to construct the Amistad International Dam, a sense of urgency greatly accelerated the tempo of archeological investigations. It was evident the reservoir project would inundate many of the sites, seriously impair others, and jeopardize those above maximum flood-pool level by making them much more accessible. A series of intensive studies was instituted to salvage the area's archeological data before they were irretrievably lost. The initial survey was conducted in the winter of 1958 by the Archeological Salvage Program Field Office of the National Park Service, Austin, Texas. Guided by its recommendations, a program of excavations in the U.S. sector of the reservoir basin has been continued on almost an annual basis by various personnel of the Texas Archeological Salvage Project, University of Texas, under contract with the National Park Service. Noteworthy also is a preliminary study of the region's paleoecology which was conducted in 1966 under the auspices of the National Science Foundation.

The Mexican side of the reservoir has not been neglected. In the fall of 1957 a cooperative project between authorities of the two countries was set up to conduct archeological investigations in the area to be flooded. Dr. Walter W. Taylor of the Dirección de Prehistoria, Mexican National Institute of Anthropology and History, was in charge of the work. A total of 63 sites of the types on the U.S. side were inventoried. The great majority of rockshelters were clustered in the area opposite the mouth of the Pecos River, which was also the only sector in which any appreciable vandalism was noted. Sites of all types were relatively rare on the Mexican side as compared with the American, and, strangely, only one series of the distinctive Pecos River Focus pictographs was found. There is an undoubted correlation between these disparities and the fact that most of the major springs in the region are on the U.S. side, where the cultural hearth of these aboriginal peoples was evidently centered.

Some of the more significant references on Amistad's archeology are listed in the bibliography.



Authority for the construction of Amistad Dam and Reservoir by the International Boundary and Water Commission was provided by the Water Treaty of 1944 between the United States and Mexico (59 Stat. 1219) and, insofar as the U.S. sector of the project is concerned, by Public Law 86-605 of July 7, 1960 (74 Stat. 360). Actual arrangements for the joint construction, operation, and maintenance of the dam and reservoir by the two Governments are based on the 1944 treaty and on pursuant minutes of the International Boundary and Water Commission. Certain provisions in these documents have a bearing on recreation planning and use and are, therefore, referenced in this master plan.

Water Treaty of 1944: Among other things the treaty established that the international boundary between the two countries—i.e., the centerline of the Rio Grande—will remain unchanged after it is obscured by the impoundment, and that public use of the reservoir surface is to be "free and common to both countries, subject to police regulation of each country in its territory." The international boundary is also the southerly, or water-side, boundary of the proposed national recreation area.

The treaty provides that the flow of water into the reservoir be measured and credited to each country in accordance with ownership of such inflows and that each country is free, at any time, to utilize its share of water for direct beneficial use or for storage in other reservoirs. While this might imply an unfavorable outlook regarding stability of the lake for recreational use, the treaty further stipulates that storage shall be maintained at the maximum possible water level consistent with flood control, irrigation use, and power requirements. As a guide, the treaty also specifies the following "order of preference" for joint use of international waters:

1. Domestic and municipal uses
2. Agriculture and stock raising
3. Electric power generation
4. Other industrial uses
5. Navigation
6. Fishing and hunting
7. Any other beneficial use which may be determined by the Commission.
Upstream to Amistad Dam in March 1968, Mexican side on left, U.S. side on right. Devils River entering Rio Grande in right distance.

Public Law 86-605: In authorizing United States participation in the Amistad Project, this act refers to and, in effect, adopts the specifications described in a September 1958 report by the U.S. Section of the International Boundary and Water Commission, entitled "Rio Grande International Storage Dams Project: Proposed Diablo Dam and Reservoir." This report is a detailed feasibility study, from the standpoint of the United States, expanding on the engineering findings in the Commission's Minute No. 207, dated June 19, 1958—also cited in the above act. Among its conclusions the minute contains the first recognition by the sponsoring agency of the project's recreation opportunities. The September 1958 study treats this in depth by including, as parts of an appendix, separate reports by the Bureau of Sport Fisheries and Wildlife on the reservoir's fish and wildlife aspects and by the National Park Service on its recreation potential (the latter had actually influenced the conclusion in Minute No. 207). The citing of these documents in the legislation established the basic authority for including outdoor recreation as one of the project purposes at Amistad. As initially conceived in the feasibility studies, responsibility for administering this use was proposed for the State level.

The September 1958 report and Minute No. 207, together with related report correspondence, were published as Senate Document No. 65, 86th Congress, 1st session, dated September 9, 1959. This is a basic background reference. On October 12, 1959, the Presidents of the two countries, meeting at Camp David, Maryland, chose the name Amistad Dam (amistad is "friendship" in Spanish) to designate this proposed structure. The cover of Senate Document No. 65 was changed to reflect the new name and the project has since been known as Amistad, but the entire contents of the publication retain the old name, Diablo.

The intent of the legislation and the international agreements on which it is based is that the operation of the Amistad Project will be coordinated with that of the existing Falcon Reservoir downstream. Insofar as the U.S. share of storage waters is concerned, some of the basic operating principles outlined for Amistad are: 1) That releases of water for flood-control purposes (together with Mexican waters, as determined by the International Boundary and Water Commission) shall be at the minimum rates practicable, and, if possible, not in excess of the safe capacity of the river channel below the dam; 2) that in regard to the generation of power, no waters will be retained solely to maintain a power head and, as a rule, the generation of power will be incidental to other releases of water, although the U.S. Section of the Commission may, when consistent with maximum feasible regulation of waters for domestic and irrigation uses, make additional releases to permit, in combination with Mexican releases, optimum generation of hydroelectric energy.

Although, by agreement between the two Sections, each country may construct its own power generating facilities, and Mexico is so proceeding, those on the U.S. side are being deferred until a future time. The penstocks, of course, are in place in the dam.

Mexico's proposed plan of operation for its share of the water stored at Amistad is believed to be based on similar principles.

A major provision of Public Law 86-605 specifies that releases of the U.S. share of waters for domestic, municipal, industrial, and irrigation purposes shall be made pursuant to order by the appropriate authority of the State of Texas. Further, in order to comply with a stipulation by the State that water available for use below Falcon Dam be not less than the amount previously available, the appropriate authority of the State shall have the exclusive responsibility for distributing additional waters stored by Amistad Dam in such a manner as will meet this stipulation.

National Park Service Administration of Recreational Use: The Act of August 7, 1946 (60 Stat. 885) provides general authority for the National Park Service to administer recreational use of areas under the jurisdiction of other Federal agencies pursuant to cooperative agreements. Such a Memorandum of Agreement between the United States Section of the International Boundary and Water Commission and the Service was executed on November 11, 1965. This agreement, approved by the Assistant Secretaries of State and Interior, provides the present basis for Service administration of public use of lands and waters in the U.S. portion of the Amistad Project.

In accordance with Article I of the agreement, the U.S. Section of the Commission will retain jurisdiction of those project lands on the American side required for the construction and operation of the dam and engineering works, and the Service will administer all other existing and future lands acquired by the Section for project purposes. The article also specifies that, subject to treaty and statutory requirements, the Section will at all times conduct its operations with consideration for the best possible recreational use and enjoyment by the public. Towards this end, the Service is to provide the Section with information as to the optimum and minimum pool levels desirable for public use.

The article further specifies that each agency shall obtain the concurrence of the other prior to making any new development or granting any concession, lease, license, or permit which could affect the other's activities or facilities.

Article II of the agreement spells out the functions of the Service, which include the following responsibilities: Prepare plans for, finance, and construct recreational facilities in coordination with the Section and other concerned Federal, State, and local agencies; negotiate and administer private concession contracts for supplying necessary visitor services related to recreational use of the project area, and arrange with appropriate State authorities for the consumptive use of any waters related to such services; promulgate and enforce such rules and regulations as are necessary or desirable for conservation and recreation purposes; establish and maintain protective, interpretive, and other facilities and services necessary for the safe and full use and enjoyment of the area, and coordinate information activities with the Section in order to facilitate public understanding of the interrelated programs of the two agencies; administer any grazing use on project lands after consultation with the Texas Parks and Wildlife Department; cooperate with State and Federal wildlife agencies as desirable for the conservation and protection of wildlife; ensure that no recreational use be permitted which is inconsistent with the laws of the State of Texas for the protection of fish and game and of the public health, safety, and welfare; and perform such other functions as are reasonably related to, or necessary for, Service administration of the project area.

Article III of the agreement outlines the functions of the Section, which include the following responsibilities: Construct, operate, and maintain the U.S. portion of Amistad Dam and Reservoir and appurtenant engineering works; consult with the Service concerning development or administration of recreational facilities or public information services to be provided in the areas retained under jurisdiction of the Section; establish and enforce rules and regulations governing public access to the dam and engineering works; establish and, in cooperation with the Service, enforce limitations governing aquatic approach to the dam and appurtenant works as may be necessary either for their efficient functioning or for public safety; and cooperate with the Service to promote coordination of recreational development and administration with the construction and operation of the dam and reservoir.

Article IV provides that the memorandum shall remain in force as written unless revised or terminated by mutual agreement, or unless termination is directed by the Secretaries of State and Interior, or until enactment by the Congress of inconsistent or superseding legislation.

Jurisdiction: The National Park Service has proprietary jurisdiction over the U.S. portion of the recreation area. Because the waters will be considered navigable, the U.S. Coast Guard regulations will apply to the American side.


Acquisition of Amistad Project lands by the International Boundary and Water Commission is in compliance with Article 23 of the 1944 Water Treaty, which reads in part:

The two governments recognize the public interest attached to the works required for the execution and performance of this treaty and agree to acquire, in accordance with their respective domestic laws, any private property that may be required for the construction of the said works.

Each section of the Commission shall determine the extent and location of any private property to be acquired within its own country and shall make the necessary requests upon its government for the acquisition of such property.

Apparently the Mexican Government already owned the lands on its side of the border in the project area and there is no question of shoreline control. With minor exceptions described below, lands on the American side have been, or are in the process of being, acquired by the U. S. Section of the Commission according to specific criteria. For those areas containing the dam and permanent operating structures the acquired title is in fee simple. For most other lands in the reservoir area below the 1144.3-foot flood-pool contour, for certain recreation development sites above that contour plus an additional site below the dam, and for all islands that will be formed at any reservoir level, the estate is "fee simple, save and except oil and gas." This title reserves the oil and gas rights to the former owner but carries a restriction against exploiting them which is expressed in either of two ways, depending on the location of the lands. In its commonest form, applying to all lands below the 1144.3-foot contour in most of the reservoir basin, the covenant stipulates that the estate remaining in the former owner is

subject to a negative easement in and upon said lands to prohibit the drilling or deepening of any well for the purpose of producing oil and/or gas, provided, however, that exploration and development of oil and/or gas under said lands will be permitted by directional drilling from locations above the 1144.3-foot elevation contour boundary of said parcels.

In all other lands acquired in fee, particularly those lying above the 1144.3-foot contour whether islands or mainland, the second and more stringent type of restriction provides that

there is excluded from said mineral rights any right of the owner thereof to enter upon said parcels of land, or to mine, drill, or explore for minerals, or produce, store, or market the same from, upon, or through the surface of said parcels.

While the latter stipulation is silent regarding permission to drill directionally from exterior locations, such a right is implied.

Exceptions: In the earliest acquisitions in areas near the dam and along the Devils River, the Boundary Commission was following a policy calling for fee title on only those lands in the basin below the 1117-foot operating-pool contour, with a flowage easement on the remainder of the lands up to the 1144.3-foot contour. The latter interest is described as a

perpetual easement to overflow, flood, and submerge lands intermittently between elevation 1117 and 1144.3 and for ingress, egress, and regress for the purpose of operation and maintenance of the Amistad Dam and Reservoir; provided that no structure for human habitation shall be constructed or maintained on said lands; and provided further that no other structures shall hereafter be constructed or maintained on said lands except as may be approved in writing by the United States Commissioner, International Boundary and Water Commission . . . .

Throughout the areas covered by this easement, the Commission also acquired the overlapping negative easement pertaining to oil and gas, but only for the zone between the 1117- and 1140-foot contours. In these cases, directional drilling was permitted above the 1140-foot elevation. Below 1117 feet, the exclusion-from-entry type of restriction on oil and gas was applied, rather than the negative easement.

Upon recommendation by the National Park Service in 1963, the Commission agreed to abandon the use of the flowage easement in subsequent acquisitions by extending the fee criterion up to the 1144.3-foot contour. In addition, the Commission determined that for those flowage easements already acquired, it would attempt to secure the additional interest for fee title if the cost were reasonable. It was also at this stage that the Commission agreed to include all islands rising above the maximum water level in the program of fee-simple (save oil and gas) acquisition, and, cost permitting, to go back and secure the additional interest on those entire islands where only the flowage easement between 1117 and 1144.3 feet had already been acquired. It appears unlikely that the Commission will be completely successful in reaching these objectives, and it is anticipated there will remain some islands and mainland strips on which the Government lacks the fee title between 1117 and 1144.3 elevation, as well as some islands above 1144.3 feet on which there is no acquired interest.

Since only minimal recreational values are attached to the Rio Grande channel upstream from where the 1117-foot contour crosses it, this crossing marks the upper limit of the proposed recreation area boundary on that river. On the Pecos and Devils Rivers, the limit is the 1144.3-foot-contour turnback.

After the maximum flood-storage level had been calculated to be the 1144.3-foot contour, redesign of the project raised this to 1145.12 feet. However, no interests or restrictions of any kind are contemplated in the Boundary Commission's acquisition program for this additional 0.82-foot-high zone because the theoretical possibility of its being flooded is so remote.

The existing 7-mile access road leading from U.S. 277 to the proposed Rough Canyon recreational site on the Devils River was acquired in the Commission's program along with lands at that site because the road was in the same ownership. The road will remain federally owned for public use. Also, right-of-way for an access link between the highway and the proposed Long Point site has been acquired.

In its lower reaches the Amistad Project necessitated relocation of U.S. 90 and 277 and the Southern Pacific railroad to new alignments, segments of which cross the recreation area. The Commission acquired the new rights-of-way and retained fee title to the portions within the recreation area. No relocation was required where U.S. 90 and the railroad cross the Pecos River arm of the reservoir, and there the Commission may acquire only a flowage easement within the pre-existing rights-of-way.


The weather at Amistad Reservoir is conducive to year round recreational use. The area has a semiarid continental-type climate, lying essentially within the diffuse transitional zone between the dry Southwest and the wetter, generally lower areas of central and southern Texas. Aridity increases northwesterly, humidity southeasterly.

Summers are hot and winters mild; the occasional snow storms are seldom heavy enough to blanket the ground. There is little disruption, therefore, of construction or visitor-use seasons attributable solely to weather.

Attempts to categorize rainfall distribution in this region are largely academic, but records show that Del Rio has an average annual precipitation of 18.58 inches, while Langtry, 50 miles to the northwest, has 14.13 inches. The pattern is erratic and highly irregular over the years; long droughts are broken by intense storms which on occasion have brought as much as twice the yearly average rainfall in less than a week.

Winds are generally from the southeast in summer and the northwest in winter. Normally they vary in intensity from 0 to 28 miles per hour, with an average of 8.8. The higher wind speeds are usually associated with winter storms.


In spite of the relatively hot and arid climate which prevails throughout most of the year, fire conditions are not considered serious because of the general lack of sufficient vegetative fuel. However, in those areas where grazing may be terminated and which are not otherwise disturbed, fire hazard will increase as the normal vegetation density is restored.


Except for the steep-walled canyons of the rivers themselves, the terrain in the reservoir vicinity is a rather uniform, moderate dissection of the gently rolling Edwards Plateau. The landscape is generally low hills and shallow open valleys, and where this surface is interrupted by the canyon system the transition in topography is usually abrupt. Largely confined to a mile in width, a variable zone containing sharply incised drainage tributaries and rough slopes extends back from the canyon rims.

The above characteristics impose no serious problems for most aspects of recreational site planning, as adequate tracts with relatively mild relief suitable for public-use developments are available along the shoreline. Such relief as there is, in fact, presents a pleasant and diversified setting for recreational activities on both land and water. However, at some of the sites, the steepness and rockiness of the slopes below flood level will make construction of ramps and other marina facilities difficult.

The reservoir scene will be divided into two distinct types as a result of water level in relation to topography. The controlling condition lies in the fact that the land elevations gradually decrease toward the downstream parts of the reservoir. Thus, impounded water there will generally overtop the canyon rims and extend out over the gentler slopes of the basin for distances up to 3 miles; in marked contrast, water at the same levels in the upstream reaches of the reservoir will always be confined within the steep canyon walls. In terms of visual impressions, the main body of the reservoir—occupying roughly the eastern half of its longitudinal limits—will consist of broad expanses of open water with long unobstructed vistas between the land and water surfaces. Clearly distinguished from this scenic province will be the narrow fiordlike ribbons of the reservoir in the western half, where the canyon rims lie above maximum water level.

Elevations within the recreation area boundaries range from 900 feet above sea level at the foot of the dam to 1,400 in the proposed development site above the Pecos-Rio Grande confluence. Some of the bordering hills in the western part of the basin exceed 1,600 feet. The average break of the surface at the canyon rims in that sector varies from 1,200 to 1,300 feet.


Except in the river bottoms and tributary canyons, much of which will be flooded by the reservoir, the soil mantle in this vicinity is generally quite thin and stony, with large areas of exposed limestone bedrock. Most of the soils are calcareous and are classified in the Rough Stony Land group of the Ector series. Higher in the profile are Del Rio clays which are found in narrow zones along most of the length of the reservoir. At several places in the downstream parts of the lake this formation will be subject to inundation, and where this occurs slumping of the overlying material can be anticipated. Such sites should be avoided in development planning. After several years of exposure to the fluctuating reservoir waters, the fallen rocky material may act as natural riprapping and more or less stabilize the banks.


The present pattern of land use in the Amistad vicinity is described in the section on Surroundings and Existing Use. Creation of the reservoir will locally affect these resource activities in various degrees ranging from complete elimination to mere modification, while wholly new types of use will appear as a result of the project. The obvious innovation is the water impoundment itself, although it has a precedent in the two small reservoirs on the Devils River—Lake Walk and Devils Lake. The entire operation of the Central Power and Light Company on this river, consisting of hydroelectric works at the two lakes and a steam plant below them, all subject to inundation, was terminated during the early stages of land acquisition for the Amistad Project.

For the most part the effect on other pre-existing uses will simply be their exclusion from areas actually flooded or required for public purposes; their continuance elsewhere in the recreation area under controlled conditions is considered compatible with the dominant resource management purpose of outdoor recreation.


Grazing: Lands in this vicinity have been used almost exclusively for sheep and goat grazing. To the extent that grazing will not be detrimental to public or project use or impair archeological values, it will continue to be allowed under regulation in the national recreation area if the adjoining landowners desire it. This policy conforms to the existing Memorandum of Agreement between the U.S. Section of the International Boundary and Water Commission and the National Park Service relating to recreation administration by the latter (which agreement, incidentally, specifies that the Texas Parks and Wildlife Department will be consulted concerning grazing activities). In accordance with policy established by the Section, preference in granting a grazing lease or permit on a particular tract of land will be given to the former owner, who will also be allowed to retain his existing stock-control fences which extend into the reservoir. Provision for reasonable access of the stock to the water is contemplated in this procedure. In general, the only lands where grazing will be excluded are those containing administrative and recreation developments, other places of heavy visitor use, islands, and the archeological sites. As a practical matter, there will be virtually no grazing in the canyon portions of the recreation area because of inaccessibility and lack of vegetation on the limestone walls. Elsewhere on the reservoir shorelands the quality and carrying capacity of the forage may actually be improved over their former condition as a result of intermittent flooding by the fluctuating waters.

Mining: Theoretically, adverse subsurface mining is possible in any part of the recreation area except lands containing the dam and permanent operating structures, because the basic land-acquisition criterion reserves the mineral (specifically, oil and gas) estate in private ownership. Practically, however, the question of resource-use compatibility does not arise because restrictions in the land deeds deny the former owners all rights of access to oil and gas through the surface of the acquired tracts. Any such activity must be by means of directional drilling from outside the takeline. There are presently a few exceptions to this condition where the Boundary Commission has been unable to acquire some islands, and where some island and mainland strips between the 1140- and 1144.3-foot contours lack the negative easement against drilling.

Residential: Still in its infancy but with a potential for rapid growth in the area immediately outside the project boundaries is the emerging new trend in land use—residential subdivisions. It is directly stimulated by the anticipation of an aquatic playground in the "front yard." This inevitable private activity cannot fail to have a bearing on management of the recreation area, but so long as it does not compete for lands identified for inclusion in the area it cannot be considered incompatible with public use of the reservoir. Cooperative county zoning regulations would minimize adverse effects on such use.


Other than changing from private to public auspices, the pre-existing limited recreational uses within the project area will be affected only as to location and capacity when the reservoir forms. None of the types will be eliminated. The area's principal recreation resource was embodied in Lake Walk and Devils Lake, which will become incorporated in Amistad Reservoir. The facilities to be flooded out of existence there include boat docks, fishing camps, a motel-cafe-camp complex, and an Air Force recreation center. The same types of developments, with much greater total capacity, will be substituted at various sites in the national recreation area.

The stream fishing formerly enjoyed along the short stretch of the Devils River below Lake Walk will simply be shifted upstream to the segment of the river within the recreation area above Devils Lake. Depending on the reservoir level at the time, the length of free-flowing river in public ownership here will vary from 2 to 10 miles during normal storage conditions.

Up Devils River to Lake Walk and Devils Lake. Both impoundments will be inundated by Amistad Reservoir but will periodically re-emerge during drawdown.

The acreage of hunting lands will of course be reduced by whatever amount is under water, but where there were no public lands at all before the project there will now be considerable areas available for public hunting.

The whole concept of outdoor recreation in the region takes on a new order of magnitude with the formation of Amistad Reservoir. Factors which will combine to generate heavy use here are the presence of a large body of water with substantial and scenically attractive recreation opportunities in a section of the country where resources of this caliber are rare, climatic conditions favorable for year-long use, and a location easily accessible to a large segment of the population. These qualities would be significant anywhere, but Amistad's setting on the international border—a distinctive lure that already accounts for considerable tourist travel in the area—sets this reservoir apart from the many impoundments to the north. The attraction will not be limited to visitors from the United States; it can also be expected to entice the residents of a warmer and drier area south of the border—a portion of Mexico almost completely devoid of water-associated outdoor recreation. The wide range of water- and land-based recreational activities for which Amistad is suitable are listed below. Potential total user demand is estimated to be one million visits annually by the end of the first 5 years of operation, increasing to two million by the year 2000.

Existing Lake Walk, to be inundated by Amistad Reservoir, suggests appearance of the latter's canyon sectors.

Sightseeing: Probably this will always be a major activity at Amistad in terms of participant numbers—both by visitors who come primarily for other recreational purposes and by those who are there just to look. Most of the latter will not be prepared or equipped to engage in other pursuits, but many may take advantage of rental or charter facilities and services.

Sightseeing will be most rewarding by boat, but will also be enjoyed by automobile, aircraft, horse, and foot. The upper canyon sections of the reservoir will have the most scenic interest, although the dam itself will be a popular attraction. Practically all U.S. visitors will want to cross the dam in order to see at least a little of Mexico. The opportunity to tour the Mexican shoreline will appeal to boaters.

Boating: Certainly this will be a major use of the Amistad Reservoir, not only as a recreational pursuit in itself but also as a means of engaging in such other activities as water skiing, skindiving, sightseeing, exploring, fishing, hunting, and secluded camping. Reasonably steady breezes and the absence of a high, wind-deflecting shoreline in the main body of the reservoir should provide attractive and relatively safe conditions for sailboating.

The Rio Grande will often have a free-flowing stretch below Langtry, its length depending on the position of the impounded water level. Even when that level reaches up into this part of the canyon, the river's current will continue to be manifest a good part of the time. During periods of proper conditions it will be possible for boats, canoes, or rafts to launch at Langtry and float the current down to a take-out point near the Pecos River confluence, a distance of about 24 miles. At higher stages of reservoir storage, combination float-power trips will be feasible. It is in this section of the reservoir that the canyon is most tortuous, sheer walled, and scenic—qualities contributing to outstanding enjoyment of this more adventuresome type of use.

Swimming: With favorable air and water temperatures throughout most of the year, swimming will be popular at Amistad. However, because of the expected fluctuation of the reservoir level, swimming pools will be a more practical type of facility than beaches to provide for this activity. Scuba diving and snorkeling from boats or shoreline will be feasible in the reservoir itself.

Camping and Picnicking: Both of these uses should prove to be exceptionally popular, not only by visitors basing here for active recreational participation but also—in this region of little water—by those who just enjoy looking at and being near bodies of water. In addition to heavy utilization of camping and picnicking facilities at formally developed sites, considerable use can be expected at primitive places along the reservoir shoreline and on islands.

Permanent camping and related recreational facilities for organized groups would be appropriate at Amistad under either special-use permit or concession operation.

Fishing: The Bureau of Sport Fisheries and Wildlife has indicated that fishing in Amistad Reservoir for largemouth bass, white bass, and white crappie will be excellent for the first few years of operation, and channel catfish will provide good fishing for many years. With adequate management it is anticipated that fishing quality can be maintained at a high level indefinitely. Construction of the project will greatly enhance ecological conditions of the Rio Grande below the dam, and, consequently, stream fishing in this reach is expected to improve considerably; moreover, access to several miles of streambank in the upper reaches of all three of the impounded rivers will be improved. Fishing in the reservoir itself will be enhanced by the construction of floating fishing docks. The Bureau estimates 100,000 man-days of fishing use annually for the entire recreation area.

Hunting: Although only a limited amount of land above operating-pool level will be in the recreation area, experience at other reservoirs indicates that it is on these lands that a great percentage of the wildlife will concentrate. As a result, hunting at Amistad should be an important recreational activity. Whitetail deer, mourning dove, and water fowl will be the major species sought, and collared peccary, rabbits, and quail to a lesser degree.

Most of the lands outside the Federal boundaries will continue to be subject to private hunting on a lease or fee basis, probably on an expanded scale as the demand increases. Generally, these lands must be crossed—if approach is from the outside—in order to reach the portions of the recreation area where hunting can be permitted, which will be those areas containing no developments and, therefore, no public access roads either. Thus, much of the hunting use in the recreation area will depend upon the private arrangements on adjacent lands. As a rule, hunting originating from within the boundaries will require the use of boats to gain access to the shorelands.

It is in the interests of both the Government and the adjacent landowners to at least mark and post the entire recreation area boundary.

Shoreline Use: Hunting, streambank fishing, primitive camping and picnicking, exploring, and sightseeing have been mentioned as types of land-associated recreation complementing the aquatic activities. Other quality uses for which Amistad's varied zone above the fluctuating water level will provide excellent opportunities are hiking, horseback riding, rock climbing, photography, nature and archeological study, or just relaxation and the enjoyment of solitude. Important to this spectrum of recreational activities are the impressive upper canyon topography, the innumerable tributary canyons and coves, and the various islands which will be isolated by the lake.

Amistad's predominant Georgetown limestone formation contains abundant marine fossils which are continually being exposed through weathering and may thus be regarded as a renewable resource, though of course not technically so. Loose pieces of rock containing the fossils may appeal to visitors as souvenirs. Individual collecting of such rocks, but not quarrying, for purely private use and enjoyment, as distinguished from that done for scientific and educational purposes normally covered by permit, should be allowed under regulations specifying localities and conditions which will preclude loss of possible scientific or interpretive values.

Other Outdoor Recreation: In addition to campgrounds, picnic areas, and swimming pools, other appropriate uses associated with permanent facilities on sites above the maximum flood level, and favored by Amistad's climate, include such sports as golf, tennis, softball, shuffleboard, target or trap shooting, archery, and bicycling. Most of these are normally the function of concession operations.

Interpretation: In order to realize the full recreation potential of the area, the administering agency has the opportunity—as well as the obligation—to interpret the natural, historic, and manmade values of the region. At Amistad the opportunity is a significant one, particularly as regards the story of prehistoric man so prominently evidenced here.

Although most of the reservoir basin's landforms are unspectacular, it is a region of highly interesting geology, particularly in the eyes of the large percentage of visitors who will come from the relatively featureless plains country. The dominant element of the landscape is the conspicuously bedded limestone series which cannot fail to draw attention. Related to this is the noteworthy ecological story to be told in the intermingling of desert, limestone upland, and gulf coastal plant and animal species in this semiarid climate. Again, most visitors will find Amistad's flora and fauna to be quite different from those of their acquaintance and they can be expected to appreciate a modest biological review. Abundant opportunities exist to interpret these values through nature trails in the planned development sites.

The outstanding archeological resources which contribute so much to Amistad's significance are important not only to science but to the visitor's recreational enjoyment. The interpretation of these features, both on-site and through museum exhibits, will have a key place in the overall program of public services.

Even in the historic period the story of man at Amistad is a fascinating one, and many facets of it merit interpretive treatment. But no chapter is more remarkable than that dealing with the reservoir project itself. Visitors will be especially interested in this impressive engineering achievement, and the background of international friendship and cooperation which led to its development should be adequately told. In addition to the actual construction of the dam, the account should cover its purposes and its relation to other water projects and conservation needs of the two countries along their common border.

South down Seminole Canyon (foreground) to confluence with Rio Grande, Mexico in background. Panther Cave is in cliff face at left of Seminole's mouth.

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Last Updated: 26-Mar-2007