Rio Grande
Overview
 
The Rio Grande is a river
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 that flows from southwestern Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...

 in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 to the Gulf of Mexico. Along the way it forms part of the Mexico – United States border. Its length varies as its course changes. According to the International Boundary and Water Commission
International Boundary and Water Commission
The International Boundary and Water Commission is an international body created in 1889 by the United States and Mexico to administer the many boundary and water-rights treaties and agreements between the two nations....

, its total length was 1896 miles (3,051 km) in the late 1980s. Depending on how it is measured, the Rio Grande is the fourth or fifth longest river system in North America. It serves as a natural border
Natural border
A natural border is a border between states which is composed of natural formations such as rivers, mountain ranges, or deserts.Having a natural border is strategically very useful, as invading armies can have a hard time crossing such a border...

 between the U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...

 of Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

 and the Mexican
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

 states of Chihuahua, Coahuila
Coahuila
Coahuila, formally Coahuila de Zaragoza , officially Estado Libre y Soberano de Coahuila de Zaragoza is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico...

, Nuevo León
Nuevo León
Nuevo León It is located in Northeastern Mexico. It is bordered by the states of Tamaulipas to the north and east, San Luis Potosí to the south, and Coahuila to the west. To the north, Nuevo León has a 15 kilometer stretch of the U.S.-Mexico border adjacent to the U.S...

, and Tamaulipas
Tamaulipas
Tamaulipas officially Estado Libre y Soberano de Tamaulipas is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 43 municipalities and its capital city is Ciudad Victoria. The capital city was named after Guadalupe Victoria, the...

.
Encyclopedia
The Rio Grande is a river
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 that flows from southwestern Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...

 in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 to the Gulf of Mexico. Along the way it forms part of the Mexico – United States border. Its length varies as its course changes. According to the International Boundary and Water Commission
International Boundary and Water Commission
The International Boundary and Water Commission is an international body created in 1889 by the United States and Mexico to administer the many boundary and water-rights treaties and agreements between the two nations....

, its total length was 1896 miles (3,051 km) in the late 1980s. Depending on how it is measured, the Rio Grande is the fourth or fifth longest river system in North America. It serves as a natural border
Natural border
A natural border is a border between states which is composed of natural formations such as rivers, mountain ranges, or deserts.Having a natural border is strategically very useful, as invading armies can have a hard time crossing such a border...

 between the U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...

 of Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

 and the Mexican
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

 states of Chihuahua, Coahuila
Coahuila
Coahuila, formally Coahuila de Zaragoza , officially Estado Libre y Soberano de Coahuila de Zaragoza is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico...

, Nuevo León
Nuevo León
Nuevo León It is located in Northeastern Mexico. It is bordered by the states of Tamaulipas to the north and east, San Luis Potosí to the south, and Coahuila to the west. To the north, Nuevo León has a 15 kilometer stretch of the U.S.-Mexico border adjacent to the U.S...

, and Tamaulipas
Tamaulipas
Tamaulipas officially Estado Libre y Soberano de Tamaulipas is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 43 municipalities and its capital city is Ciudad Victoria. The capital city was named after Guadalupe Victoria, the...

. A very short stretch of the river serves as the boundary between the U.S. states of Texas and New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...

. The tremendous water use of big cities and vast irrigated acreage along the river has taken a heavy toll on the river's flow; less than a fifth of its historical discharge reaches the sea today. Near the river's mouth, the heavily irrigated Rio Grande Valley
Rio Grande Valley
The Rio Grande Valley or the Lower Rio Grande Valley, informally called The Valley, is an area located in the southernmost tip of South Texas...

 is an important agricultural region.

The Rio Grande's watershed
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

 covers 182200 square miles (471,895.8 km²) Many endorheic basins are situated within, or adjacent to, the Rio Grande's basin, and these are sometimes included in the river basin's total area, increasing its size to about 336000 square miles (870,236 km²).

The Rio Grande is one of nineteen Great Waters recognized by the America's Great Waters Coalition.

Geography

The Rio Grande rises in the eastern part of the Rio Grande National Forest
Rio Grande National Forest
Rio Grande National Forest is a 1.86 million acre U.S. National Forest located in southwestern Colorado. The forest encompasses the San Luis Valley, which is the world's largest agricultural alpine valley, as well as one of the worlds largest high deserts located around mountains. The...

 in the U.S. state of Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...

. The river is formed by the joining of several streams at the base of Canby Mountain, just east of the Continental Divide. From there, it flows through the San Luis Valley
San Luis Valley
The San Luis Valley is an extensive alpine valley in the U.S. states of Colorado and New Mexico covering approximately and sitting at an average elevation of above sea level. The valley sits atop the Rio Grande Rift and is drained to the south by the Rio Grande River, which rises in the San Juan...

, then south into New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...

, passing through Espanola
Española, New Mexico
Española also known as Espanola , is a city primarily in Rio Arriba County, New Mexico, in the United States. A portion of the central and eastern section of the city is in Santa Fe County. Española was founded in 1880 as a railroad village, incorporated as a city in 1925. The city is situated in...

, Albuquerque
Albuquerque, New Mexico
Albuquerque is the largest city in the state of New Mexico, United States. It is the county seat of Bernalillo County and is situated in the central part of the state, straddling the Rio Grande. The city population was 545,852 as of the 2010 Census and ranks as the 32nd-largest city in the U.S. As...

, and Las Cruces
Las Cruces, New Mexico
Las Cruces, also known as "The City of the Crosses", is the county seat of Doña Ana County, New Mexico, United States. The population was 97,618 in 2010 according to the 2010 Census, making it the second largest city in the state....

 to El Paso
El Paso, Texas
El Paso, is a city in and the county seat of El Paso County, Texas, United States, and lies in far West Texas. In the 2010 census, the city had a population of 649,121. It is the sixth largest city in Texas and the 19th largest city in the United States...

, Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

. Below El Paso it serves as part of the border between the United States and Mexico. The official river border measurement ranges from 889 miles (1,430.7 km) to 1248 miles (2,008.5 km), depending on how the river is measured. A major tributary, the Rio Conchos
Rio Conchos
The Rio Conchos is a large river in the Mexican state of Chihuahua. It joins the Río Bravo del Norte at the town of Ojinaga, Chihuahua.-Description:...

, enters at Ojinaga, Chihuahua, below El Paso, and supplies most of the water in the border segment. Other well-known tributaries include the Pecos
Pecos River
The headwaters of the Pecos River are located north of Pecos, New Mexico, United States, at an elevation of over 12,000 feet on the western slope of the Sangre de Cristo mountain range in Mora County. The river flows for through the eastern portion of that state and neighboring Texas before it...

 and the smaller Devils
Devils River (Texas)
The Devils River is a pristine, whitewater river in southwestern Texas, USA. It begins in northwest Sutton County, at , where six watercourses come together, Dry Devils River, Granger Draw, House Draw, Jackson, Flat Rock Draw, and Rough Canyon...

, which join the Rio Grande on the site of Amistad Dam
Amistad Reservoir
Amistad Reservoir is a reservoir on the Rio Grande at its confluence with the Devils River 12 miles northwest of Del Rio, Texas, USA. The lake is bounded by Val Verde County on the Texas side of the international border, and the state of Coahuila on the Mexican side of the border...

. Despite its name and length, the Rio Grande is not navigable by ocean-going ships, nor do smaller passenger boats or cargo barges use it as a route. It is barely navigable at all, except by small boats in a few places.

The Rio Grande rises in high mountains and flows for much of its length at high elevation; El Paso is 3762 feet (1,147 m) above sea level
Sea level
Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...

. In New Mexico, the river flows through the Rio Grande Rift
Rio Grande Rift
The Rio Grande Rift is a north-trending continental rift zone. It separates the Colorado Plateau in the west from the interior of the North American craton on the east. The rift extends from central Colorado in the north to the state of Chihuahua, Mexico in the south. The rift zone consists of four...

 from one sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....

-filled basin to another, cutting canyon
Canyon
A canyon or gorge is a deep ravine between cliffs often carved from the landscape by a river. Rivers have a natural tendency to reach a baseline elevation, which is the same elevation as the body of water it will eventually drain into. This forms a canyon. Most canyons were formed by a process of...

s between the basins and supporting a fragile bosque
Bosque
Bosque is the name for areas of gallery forest found along the riparian flood plains of stream and river banks in the southwestern United States...

 ecosystem on its flood plain. From El Paso eastward, the river flows through desert
Desert
A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...

. Only in the sub-tropical lower Rio Grande Valley
Rio Grande Valley
The Rio Grande Valley or the Lower Rio Grande Valley, informally called The Valley, is an area located in the southernmost tip of South Texas...

 is there extensive irrigated agriculture. The river ends in a small sand
Sand
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...

y delta
River delta
A delta is a landform that is formed at the mouth of a river where that river flows into an ocean, sea, estuary, lake, reservoir, flat arid area, or another river. Deltas are formed from the deposition of the sediment carried by the river as the flow leaves the mouth of the river...

 at the Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...

. During portions of 2001 and 2002 the mouth of the Rio Grande was blocked by a sandbar. In the fall of 2003 the sandbar was cleared by high river flows of about 7063 cuft/s.

Millions of years ago, during the Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...

, the Rio Grande ended at the southern end of the Rio Grande Rift in Lake Cabeza de Vaca. About one million years ago (mya), the stream was "captured" and began to flow east.

Navigation

Navigation was active during much of the nineteenth century, with over 200 different steamboat
Steamboat
A steamboat or steamship, sometimes called a steamer, is a ship in which the primary method of propulsion is steam power, typically driving propellers or paddlewheels...

s operating between the river's mouth close to Brownsville
Brownsville, Texas
Brownsville is a city in the southernmost tip of the state of Texas, in the United States. It is located on the northern bank of the Rio Grande, directly north and across the border from Matamoros, Tamaulipas, Mexico. Brownsville is the 16th largest city in the state of Texas with a population of...

, and Rio Grande City, Texas
Rio Grande City, Texas
Rio Grande City is a city in and the county seat of Starr County, Texas, United States. The population was 13,834 at the 2010 census. The city is 41 miles west of McAllen. It is the hometown of former Commander of U.S. Forces in Iraq, General Ricardo Sanchez. The city also holds the March record...

. Many steamboats from the Ohio
Ohio River
The Ohio River is the largest tributary, by volume, of the Mississippi River. At the confluence, the Ohio is even bigger than the Mississippi and, thus, is hydrologically the main stream of the whole river system, including the Allegheny River further upstream...

 and Mississippi rivers
Mississippi River
The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...

 were requisitioned by the US Government and moved to the Rio Grande during the Mexican War
Mexican–American War
The Mexican–American War, also known as the First American Intervention, the Mexican War, or the U.S.–Mexican War, was an armed conflict between the United States and Mexico from 1846 to 1848 in the wake of the 1845 U.S...

 in 1846. They provided transport for the U.S. Army, under General Zachary Taylor
Zachary Taylor
Zachary Taylor was the 12th President of the United States and an American military leader. Initially uninterested in politics, Taylor nonetheless ran as a Whig in the 1848 presidential election, defeating Lewis Cass...

 to invade Monterrey, Mexico, via Camargo Municipality, Tamaulipas. Army engineers
United States Army Corps of Engineers
The United States Army Corps of Engineers is a federal agency and a major Army command made up of some 38,000 civilian and military personnel, making it the world's largest public engineering, design and construction management agency...

 recommended that with small improvements the river could easily be made navigable as far north as El Paso. Those recommendations were never acted upon.

The Brownsville & Matamoros International Bridge
Brownsville & Matamoros International Bridge
The Brownsville & Matamoros International Bridge, also known as B&M International Bridge, Brownsville-Matamoros International Bridge and Express Bridge, is one of three international bridges that cross the U.S.-Mexico border between the cities of Brownsville, Texas, and Matamoros, Tamaulipas.It is...

 is a large swing bridge
Swing bridge
A swing bridge is a movable bridge that has as its primary structural support a vertical locating pin and support ring, usually at or near to its centre of gravity, about which the turning span can then pivot horizontally as shown in the animated illustration to the right...

 that dates back to 1910 and is still in use today by automobiles and railroad trains, connecting Brownsville, Texas with Matamoros, Tamaulipas
Matamoros, Tamaulipas
Matamoros, officially known as Heroica Matamoros, is a city in the northeastern part of Tamaulipas, in the country of Mexico. It is located on the southern bank of the Rio Grande, directly across the border from Brownsville, Texas, in the United States. Matamoros is the second largest and second...

. It has not been opened since the early 1900s however, when the last of the big steamboats disappeared. The bridge is now operated by the Brownsville and Matamoros Bridge Company, a joint venture between the Mexican government and the Union Pacific Railroad
Union Pacific Railroad
The Union Pacific Railroad , headquartered in Omaha, Nebraska, is the largest railroad network in the United States. James R. Young is president, CEO and Chairman....

.

At the mouth of the Rio Grande, on the Mexican side, was the large commercial port of Bagdad
Bagdad, Tamaulipas
Bagdad, Tamaulipas, Mexico was a town established in 1848 on the south bank of the mouth of the Río Grande. Moreover, this town is also known as the Port of Bagdad or the Port of Matamoros, since it is inside the municipality of Matamoros, Tamaulipas...

. During the American Civil War
American Civil War
The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...

, this was the only legitimate port of the Confederacy. European warships anchored offshore enforced this port's neutrality throughout the US Civil War, with occasional stare downs with the Yankee Navy blockaders
Union blockade
The Union Blockade, or the Blockade of the South, took place between 1861 and 1865, during the American Civil War, when the Union Navy maintained a strenuous effort on the Atlantic and Gulf Coast of the Confederate States of America designed to prevent the passage of trade goods, supplies, and arms...

. It was a shallow draft river port, with several smaller vessels that hauled cargo to and from the deeper draft cargo ships anchored off shore. These deeper draft ships could not cross the shallow sandbar
Shoal
Shoal, shoals or shoaling may mean:* Shoal, a sandbank or reef creating shallow water, especially where it forms a hazard to shipping* Shoal draught , of a boat with shallow draught which can pass over some shoals: see Draft...

 at the mouth of the river. The port's commerce was European military supplies, in exchange for bales of cotton.

History

In the 1800s, the river marked the disputed border between Mexico and the nascent Republic of Texas
Republic of Texas
The Republic of Texas was an independent nation in North America, bordering the United States and Mexico, that existed from 1836 to 1846.Formed as a break-away republic from Mexico by the Texas Revolution, the state claimed borders that encompassed an area that included all of the present U.S...

; Mexico marked the border at the Nueces River
Nueces River
The Nueces River is a river in the U.S. state of Texas, approximately long. It drains a region in central and southern Texas southeastward into the Gulf of Mexico. It is the southernmost major river in Texas northeast of the Rio Grande...

. The disagreement provided part of the rationale for the US invasion of Mexico
Mexican–American War
The Mexican–American War, also known as the First American Intervention, the Mexican War, or the U.S.–Mexican War, was an armed conflict between the United States and Mexico from 1846 to 1848 in the wake of the 1845 U.S...

 in 1846, after Texas had been admitted as a new state. Since 1848, the Rio Grande has marked the boundary between Mexico and the United States from the twin cities of El Paso, Texas, and Ciudad Juárez, Chihuahua
Ciudad Juárez
Ciudad Juárez , officially known today as Heroica Ciudad Juárez, but abbreviated Juárez and formerly known as El Paso del Norte, is a city and seat of the municipality of Juárez in the Mexican state of Chihuahua. Juárez's estimated population is 1.5 million people. The city lies on the Rio Grande...

, to the Gulf of Mexico. As such, crossing the river was the escape route used by some Texas slaves
Slavery
Slavery is a system under which people are treated as property to be bought and sold, and are forced to work. Slaves can be held against their will from the time of their capture, purchase or birth, and deprived of the right to leave, to refuse to work, or to demand compensation...

 to seek freedom. Mexico had liberal colonization policies and had abolished slavery in 1828.

In 1944 the US and Mexico signed a treaty regarding the river, and in 1997 the US designated the Rio Grande as one of the American Heritage Rivers
American Heritage Rivers
American Heritage Rivers are designated by the United States Environmental Protection Agency to receive special attention to further three objectives: natural resource and environmental protection, economic revitalization, and historic and cultural preservation.The American Heritage Rivers...

. Two portions of the Rio Grande are designated National Wild and Scenic Rivers System, one in northern New Mexico and the other in Texas, at Big Bend National Park
Big Bend National Park
Big Bend National Park is a national park located in the U.S. state of Texas. Big Bend has national significance as the largest protected area of Chihuahuan Desert topography and ecology in the United States, which includes more than 1,200 species of plants, more than 450 species of birds, 56...

.

In the summer of 2001, a 328 feet (100 m) wide sandbar
Shoal
Shoal, shoals or shoaling may mean:* Shoal, a sandbank or reef creating shallow water, especially where it forms a hazard to shipping* Shoal draught , of a boat with shallow draught which can pass over some shoals: see Draft...

 formed at the mouth of the river, marking the first time in recorded history that the Rio Grande failed to empty into the Gulf of Mexico. The sandbar was subsequently dredged, but it re-formed almost immediately. Spring rains the following year flushed the re-formed sandbar out to sea, but it returned in the summer of 2002. As of the fall of 2003, the river once again reaches the Gulf.

River modifications

The United States and Mexico share the water of the river under a series of agreements administered by the joint US-Mexico Boundary and Water Commission. The most notable of these treaties were signed in 1906 and 1944.

Use of that water belonging to the United States is regulated by the Rio Grande Compact
Rio Grande Compact
The Rio Grande Compact is a treaty signed in 1938 in the United States between the states of Colorado, New Mexico, and Texas, and approved by the United States Congress, to equitably apportion the waters of the Rio Grande Basin.-Passage:...

, an interstate pact between Colorado, New Mexico, and Texas. The water of the Rio Grande is over-appropriated: that is, there are more users for the water than there is water in the river. Because of both drought and overuse, the section from El Paso downstream through Ojinaga was recently tagged "The Forgotten River" by those wishing to bring attention to the river's deteriorated condition.

There are a number of dams on the Rio Grande, including Cochiti Dam
Cochiti Dam
The Cochiti Dam is an earthen fill dam located on the Rio Grande River in Sandoval County, New Mexico approximately 50 miles north of Albuquerque, New Mexico in the United States...

, Elephant Butte Dam
Elephant Butte Dam
Elephant Butte Dam or Elephant Butte Dike is a concrete gravity dam on the Rio Grande near Truth or Consequences, New Mexico. The river was dammed here, impounding the Elephant Butte Reservoir for recreation and agriculture, lessening the downstream flow from a Rio Bravo to a stream a foot deep.The...

, Caballo Dam
Caballo Dam
Caballo Dam is an earthen dam on the Rio Grande about downstream from Truth or Consequences, New Mexico, United States. In conjunction with Elephant Butte Dam, which lies about upstream, it regulates the discharge of the river in the lower Rio Grande Valley of New Mexico. Caballo serves as an...

, Amistad Dam
Amistad Dam
Amistad Dam is a large dam across the Rio Grande on the United States-Mexico border. It serves to store water for irrigation and generate hydroelectricity. The dam was first proposed in a 1944 treaty between the United States and Mexico. Construction began in 1963 and was finished in 1969, with the...

, Falcon Dam
Falcon Dam
Falcon Dam is an earthen embankment dam on the Rio Grande between Starr County in the U.S. state of Texas and the city of Nueva Ciudad Guerrero in the Mexican state of Tamaulipas...

, Anzalduas Dam, and Retamal Dam. In southern New Mexico and the upper portion of the Texas border segment, the river's discharge
Discharge (hydrology)
In hydrology, discharge is the volume rate of water flow, including any suspended solids , dissolved chemical species and/or biologic material , which is transported through a given cross-sectional area...

 dwindles. Diversions, mainly for agricultural irrigation, have increased the natural decrease in flow such that by the time the river reaches Presidio, Texas
Presidio, Texas
Presidio is a city in Presidio County, Texas, United States. It stands on the Rio Grande , on the opposite side of the U.S.-Mexico border from Ojinaga, Chihuahua. The population was 4,167 at the 2000 census....

, there is little or no water. Below Presidio the Rio Conchos
Rio Conchos
The Rio Conchos is a large river in the Mexican state of Chihuahua. It joins the Río Bravo del Norte at the town of Ojinaga, Chihuahua.-Description:...

 restores the flow of water. Near Presidio the river's discharge is frequently zero. Its average discharge is 178 cuft/s, down from 945 cuft/s at Elephant Butte Dam. Supplemented by other tributaries the Rio Grande's discharge increases to its maximum annual average of 3504 cuft/s near Rio Grande City, Texas
Rio Grande City, Texas
Rio Grande City is a city in and the county seat of Starr County, Texas, United States. The population was 13,834 at the 2010 census. The city is 41 miles west of McAllen. It is the hometown of former Commander of U.S. Forces in Iraq, General Ricardo Sanchez. The city also holds the March record...

. Large diversions for irrigation below Rio Grande City reduce the river's average flow to 889 cuft/s at Brownsville and Matamoros.

Crossings

The major international border crossings along the river are at Ciudad Juárez and El Paso; Presidio, Texas
Presidio, Texas
Presidio is a city in Presidio County, Texas, United States. It stands on the Rio Grande , on the opposite side of the U.S.-Mexico border from Ojinaga, Chihuahua. The population was 4,167 at the 2000 census....

, and Ojinaga, Chihuahua; Laredo, Texas
Laredo, Texas
Laredo is the county seat of Webb County, Texas, United States, located on the north bank of the Rio Grande in South Texas, across from Nuevo Laredo, Tamaulipas, Mexico. According to the 2010 census, the city population was 236,091 making it the 3rd largest on the United States-Mexican border,...

, and Nuevo Laredo, Tamaulipas
Nuevo Laredo
Nuevo Laredo is a city located in the Municipality of Nuevo Laredo in the Mexican state of Tamaulipas. The city lies on the banks of the Río Grande, across from the United States city of Laredo, Texas. The 2010 census population of the city was 373,725. Nuevo Laredo is part of the Laredo-Nuevo...

; McAllen-Hidalgo, Texas
McAllen, Texas
McAllen is the largest city in Hidalgo County, Texas, United States. It is located at the southern tip of Texas in an area known as the Rio Grande Valley and is part of the . Its southern boundary is located about five miles from the U.S.–Mexico border and the Mexican city of Reynosa, the Rio...

, and Reynosa, Tamaulipas
Reynosa
Reynosa is a border city in the northern part of Tamaulipas, in the country of Mexico. It is located on the southern bank of the Rio Grande, directly across the border from McAllen, Texas in the United States. As of 2010, the city of Reynosa counts with a population of 607,532...

; and Brownsville, Texas
Brownsville, Texas
Brownsville is a city in the southernmost tip of the state of Texas, in the United States. It is located on the northern bank of the Rio Grande, directly north and across the border from Matamoros, Tamaulipas, Mexico. Brownsville is the 16th largest city in the state of Texas with a population of...

, and Matamoros, Tamaulipas
Matamoros, Tamaulipas
Matamoros, officially known as Heroica Matamoros, is a city in the northeastern part of Tamaulipas, in the country of Mexico. It is located on the southern bank of the Rio Grande, directly across the border from Brownsville, Texas, in the United States. Matamoros is the second largest and second...

. Other notable border towns are the Texas/Coahuila pairings of Del Rio
Del Rio, Texas
Del Rio is a border city in and the county seat of Val Verde County, Texas, United States.. Del Rio is connected with Ciudad Acuña via the Lake Amistad Dam International Crossing and Del Río-Ciudad Acuña International Bridge...

Ciudad Acuña
Ciudad Acuña
Ciudad Acuña, also known simply as Acuña, is a city located in the Mexican state of Coahuila, at and a mean height above sea level of 271 meters...

 and Eagle Pass
Eagle Pass, Texas
Eagle Pass is a city in and the county seat of Maverick County The population was 27,183 as of the 2010 census.Eagle Pass borders the city of Piedras Negras, Coahuila, Mexico, which is to the southwest and across the Rio Grande. The Eagle Pass-Piedras Negras Metropolitan Area is one of six...

Piedras Negras
Piedras Negras, Coahuila
-Natural Resources:This region generates a large amount of the national production of coal, one of the most economically important non-metallic minerals in the state.-Tourism:Piedras Negras' main tourist attractions are:...

.

Names and pronunciation

is Spanish
Spanish language
Spanish , also known as Castilian , is a Romance language in the Ibero-Romance group that evolved from several languages and dialects in central-northern Iberia around the 9th century and gradually spread with the expansion of the Kingdom of Castile into central and southern Iberia during the...

 for "Big River" and means "Great River of the North". In English
English language
English is a West Germanic language that arose in the Anglo-Saxon kingdoms of England and spread into what was to become south-east Scotland under the influence of the Anglian medieval kingdom of Northumbria...

, Rio Grande is pronounced either ˈriːoʊ ˈɡrænd or /ˈriːoʊ ˈɡrɑːndeɪ/. Because río means "river" in Spanish, the phrase Rio Grande River is redundant.

In Mexico it is known as Río Bravo or , bravo meaning (among other things) "furious" or "agitated".

Historically, the Pueblo
Pueblo
Pueblo is a term used to describe modern communities of Native Americans in the Southwestern United States of America. The first Spanish explorers of the Southwest used this term to describe the communities housed in apartment-like structures built of stone, adobe mud, and other local material...

 and Navajo peoples also had names for the Rio Grande/Rio Bravo:
  • mets'ichi chena, Keresan
    Keresan languages
    Keresan , also Keres , is a group of seven related languages spoken by Keres Pueblo peoples in New Mexico, U.S.A.. Each is mutually intelligible with its closest neighbors...

    , "Big River"
  • posoge, Tewa
    Tewa language
    Tewa is a Kiowa–Tanoan language spoken by Pueblo people, mostly in the Rio Grande valley in New Mexico north of Santa Fe. The 1980 census counted 1,298 speakers, almost all of whom are bilingual in English...

    , "Big River"
  • paslápaane, Tiwa
    Tiwa languages
    Tiwa is a group of two, possibly three, related Tanoan languages spoken by the Tiwa Pueblo, and possibly Piro Pueblo, groups in the U.S...

    , "Big River", Towa
    Jemez language
    Jemez is a Kiowa–Tanoan language spoken by the Jemez Pueblo people in New Mexico. It has no written form, as tribal rules do not allow it.-Demographics:...

    , "Great Waters"


The four Pueblo names likely predated the Spanish entrada by several centuries.
}}, Navajo
Navajo language
Navajo or Navaho is an Athabaskan language spoken in the southwestern United States. It is geographically and linguistically one of the Southern Athabaskan languages .Navajo has more speakers than any other Native American language north of the...

, "Female River" (the direction south is female in Navajo cosmology)

Rio del Norte was most commonly used for the upper Rio Grande (roughly, within the present-day borders of New Mexico) from Spanish colonial
Spanish colonization of the Americas
Colonial expansion under the Spanish Empire was initiated by the Spanish conquistadores and developed by the Monarchy of Spain through its administrators and missionaries. The motivations for colonial expansion were trade and the spread of the Christian faith through indigenous conversions...

 times to the end of the Mexican period in the mid-19th century. This use was first documented by the Spanish in 1582. Early American settlers in south Texas
South Texas
South Texas is a region of the U.S. state of Texas that lies roughly south of and including San Antonio. The southern and western boundary is the Rio Grande River, and to the east it is the Gulf of Mexico. The population of this region is about 3.7 million. The southern portion of this region is...

 began to use the modern 'English' name Rio Grande. By the late 19th century, in the United States, the name Rio Grande had become standard in being applied to the entire river, from Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...

 to the sea.

By 1602, Río Bravo had become the standard Spanish name for the lower river, below its confluence with the Rio Conchos
Rio Conchos
The Rio Conchos is a large river in the Mexican state of Chihuahua. It joins the Río Bravo del Norte at the town of Ojinaga, Chihuahua.-Description:...

.

Tributaries

The largest tributary of the Rio Grande by discharge
Discharge (hydrology)
In hydrology, discharge is the volume rate of water flow, including any suspended solids , dissolved chemical species and/or biologic material , which is transported through a given cross-sectional area...

 is the Rio Conchos, which contributes almost twice as much water as any other. In terms of drainage basin
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

 size the Pecos River is the largest.
Tributary
Tributary
A tributary or affluent is a stream or river that flows into a main stem river or a lake. A tributary does not flow directly into a sea or ocean...

Average discharge Drainage basin
cu ft/s m3/s sq mi km2
San Juan River
San Juan River (Tamaulipas)
The San Juan River is the largest and most important river in the Mexican state of Nuevo León. The river feeds the El Cuchillo Dam, which provides the city of Monterrey with water. The San Juan River basin has a total surface area of . The San Juan River is a contributor to the Rio Grande...

36810.4 1295033,540.3
Rio Alamo
Rio Alamo
The Rio Alamo, or Río Álamo, is a stream in the state of Tamaulipas, Mexico, and is a tributary of the Rio Grande. It is impounded by Las Blancas Dam, which was completed in 2001 and diverts water to the Marte Gómez Reservoir on the Rio San Juan, another tributary of the Rio Grande.The Rio Alamo...

1303.7 16754,338.2
Rio Salado 35410 2332360,406.3
Rio San Rodrigo
Rio San Rodrigo
The Rio San Rodrigo is a stream in the state of Coahuila, Mexico, and is a tributary of the Rio Grande.The Rio San Rodrigo enters the Rio Grande at Rio Grande river kilometer 834, at El Moral, Coahuila and about south of Quemado, Texas.The Rio San Rodrigo originates in the Sierra Madre Oriental...

1303.7 10502,719.5
Devils River
Devils River (Texas)
The Devils River is a pristine, whitewater river in southwestern Texas, USA. It begins in northwest Sutton County, at , where six watercourses come together, Dry Devils River, Granger Draw, House Draw, Jackson, Flat Rock Draw, and Rough Canyon...

36210.3 137354.8
Pecos River
Pecos River
The headwaters of the Pecos River are located north of Pecos, New Mexico, United States, at an elevation of over 12,000 feet on the western slope of the Sangre de Cristo mountain range in Mora County. The river flows for through the eastern portion of that state and neighboring Texas before it...

2657.5 44402115,000.7
Rio Conchos
Rio Conchos
The Rio Conchos is a large river in the Mexican state of Chihuahua. It joins the Río Bravo del Norte at the town of Ojinaga, Chihuahua.-Description:...

84824 2640068,375.7
Rio Puerco 39.51.1 735019,036.4
Jemez River
Jemez River
The Jemez River is a tributary of the Rio Grande in the U.S. state of New Mexico. The river is formed by the confluence of the East Fork Jemez River and San Antonio Creek, which drain a number of tributaries in the area of the Jemez Mountains and Santa Fe National Forest. The Jemez River is about ...

59.51.7 10382,688.4
Santa Fe River
Santa Fe River (New Mexico)
The Santa Fe River is a tributary of the Rio Grande in northern New Mexico. It starts in the Sangre de Cristo mountain range and passes through the state capital, Santa Fe providing approximately 40% of the city's water supply. It is an...

10.90.3086536323 231598.3
Rio Chama 57116.2 31448,142.9
Conejos River
Conejos River
The Conejos River is a tributary of the Rio Grande, approximately long, in south-central Colorado in the United States. It drains a scenic area of the eastern San Juan Mountains west of the San Luis Valley.-Description:...

1765

See also

  • List of Texas rivers
  • Rio Grande Wild and Scenic River
    Rio Grande Wild and Scenic River
    The Rio Grande Wild and Scenic River protects a 196 mile portion of the Rio Grande in Texas. Parts of Brewster, Terrell, and Val Verde counties are included in this section of the river....

  • Rio Grande Valley
    Rio Grande Valley
    The Rio Grande Valley or the Lower Rio Grande Valley, informally called The Valley, is an area located in the southernmost tip of South Texas...

  • Rio Grande Gorge
    Rio Grande Gorge
    The Rio Grande Gorge runs from northwest to southeast of Taos, New Mexico, through the basalt flows of the Taos Plateau volcanic field. The gorge depth is 800 feet just south of the Gorge Bridge, which spans the gorge ten miles northwest of Taos....

  • Rio Grande Trail
    Rio Grande Trail
    The Rio Grande Trail is a proposed long distance trail along the Rio Grande in the U.S. state of New Mexico. The river extends over 1,800 total miles, some of which pass though the heart of New Mexico. It is the state's primary drainage feature and most valuable natural and cultural resource...

  • Rio Grande Project
    Rio Grande Project
    The Rio Grande Project is a United States Bureau of Reclamation irrigation, hydroelectricity, flood control, and water diversion project, begun in 1905, that taps the Rio Grande in the states of New Mexico and Texas, in the United States. of irrigated land, in a strip of land along the river no...

  • Big Bend National Park
    Big Bend National Park
    Big Bend National Park is a national park located in the U.S. state of Texas. Big Bend has national significance as the largest protected area of Chihuahuan Desert topography and ecology in the United States, which includes more than 1,200 species of plants, more than 450 species of birds, 56...

  • Chihuahuan Desert
    Chihuahuan Desert
    The Chihuahuan Desert is a desert, and an ecoregion designation, that straddles the U.S.-Mexico border in the central and northern portions of the Mexican Plateau, bordered on the west by the extensive Sierra Madre Occidental range, and overlaying northern portions of the east range, the Sierra...

  • Trans-Pecos
    Trans-Pecos
    The term Trans-Pecos, as originally defined in 1887 by the Texas geologist Robert T. Hill, refers to the portion of Texas that lies west of the Pecos River. The term is considered synonymous with "Far West Texas", a subdivision of West Texas...

  • West Texas
    West Texas
    West Texas is a vernacular term applied to a region in the southwestern quadrant of the United States that primarily encompasses the arid and semi-arid lands in the western portion of the state of Texas....


  • Sources

    • Paul Horgan, Great River: The Rio Grande in North American History. Volume 1, Indians and Spain. Vol. 2, Mexico and the United States. 2 Vols. in 1, 1038 pages - Wesleyan University Press 1991, 4th Reprint, ISBN 0-8195-6251-3

    External links

    The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
     
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