Rio Grande

For other uses, see Rio Grande (disambiguation).

"Rio Bravo" redirects here. For other uses, see Rio Bravo (disambiguation).

Rio Grande
Río Bravo del Norte, Tooh Baʼáadii (Navajo), Kótsoi (Jicarilla Apache)
The Rio Grande in Texas, c. 1899
Countries	United States, Mexico
States	Colorado, New Mexico, Texas, Chihuahua, Coahuila, Nuevo León, Tamaulipas
Tributaries
- left	Red River, Rio Hondo, Rio Pueblo de Taos, Embudo River, Santa Fe River, Galisteo Creek, Alamito Creek, Terlingua Creek, Pecos River, Devils River
- right	Conejos River, Rio Chama, Rio Conchos, Salado River, Rio Alamo, San Juan River
Source	Canby Mountain, Continental Divide
- location	San Juan Mountains, Rio Grande National Forest, Colorado, United States
- elevation	12,000 ft (3,658 m)
- coordinates	37°47′52″N 107°32′18″W
Mouth	Gulf of Mexico
- location	Cameron County, Texas; Matamoros, Tamaulipas
- elevation	0 ft (0 m)
- coordinates	25°57′22″N 97°8′43″W
Length	1,896 mi (3,051 km)
Basin	182,200 sq mi (471,900 km2)
Discharge	for Eagle Pass, Texas/Piedras Negras, Coahuila
- average	2,403 cu ft/s (68 m3/s)
- max	964,000 cu ft/s (27,297 m3/s)
- min	24 cu ft/s (1 m3/s)
Map of the Rio Grande drainage basin

The Rio Grande (known in Mexico as the Río Bravo del Norte, or simply Río Bravo) is a river that flows from southwestern Colorado in the United States to the Gulf of Mexico. Along the way it forms part of the Mexico – United States border. According to the International Boundary and Water Commission, its total length was 1,896 miles (3,051 km) in the late 1980s, though course shifts occasionally result in length changes. Depending on how it is measured, the Rio Grande is the fourth or fifth longest river system in North America.

The river serves as a natural border between the U.S. state of Texas and the Mexican states of Chihuahua, Coahuila, Nuevo León, and Tamaulipas. A very short stretch of the river serves as the boundary between the U.S. states of Texas and New Mexico. Since the mid–20th century, heavy water consumption of farms and cities along the river has left only 20% of its natural discharge to flow to the Gulf. Near the river's mouth, the heavily irrigated Rio Grande Valley is an important agricultural region. The Rio Grande is one of 19 Great Waters recognized by the America's Great Waters Coalition.

The Rio Grande's watershed covers 182,200 square miles (472,000 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 336,000 square miles (870,000 km²).

Geography

The Rio Grande rises in the eastern part of the Rio Grande National Forest in the U.S. state of Colorado. 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, then south into New Mexico, passing through Espanola, Albuquerque, and Las Cruces to El Paso, Texas. 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 (1,431 km) to 1,248 miles (2,008 km), depending on how the river is measured. A major tributary, the Rio Conchos, enters at Ojinaga, Chihuahua, below El Paso, and supplies most of the water in the border segment. Other well-known tributaries include the Pecos and the smaller Devils, which join the Rio Grande on the site of Amistad Dam. 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 3,762 feet (1,147 m) above sea level. In New Mexico, the river flows through the Rio Grande Rift from one sediment-filled basin to another, cutting canyons between the basins and supporting a fragile bosque ecosystem on its flood plain. From El Paso eastward, the river flows through desert. Only in the sub-tropical lower Rio Grande Valley is there extensive irrigated agriculture. The river ends in a small sandy delta at the Gulf of Mexico. 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 7,063 cubic feet per second (200 m³/s).

Millions of years ago, during the Miocene, 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 steamboats operating between the river's mouth close to Brownsville, and Rio Grande City, Texas. Many steamboats from the Ohio and Mississippi rivers were requisitioned by the US Government and moved to the Rio Grande during the Mexican War in 1846. They provided transport for the U.S. Army, under General Zachary Taylor to invade Monterrey, Mexico, via Camargo Municipality, Tamaulipas. Army engineers 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 is a large swing bridge that dates back to 1910 and is still in use today by automobiles and railroad trains, connecting Brownsville, Texas with Matamoros, Tamaulipas. 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.

At the mouth of the Rio Grande, on the Mexican side, was the large commercial port of Bagdad. During the American Civil War, 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. 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 at the mouth of the river. The port's commerce was European military supplies, in exchange for bales of cotton.

History

The Upper Rio Grande near Creede, Colorado.

In the 1800s, the river marked the disputed border between Mexico and the nascent Republic of Texas; Mexico marked the border at the Nueces River. The disagreement provided part of the rationale for the US invasion of Mexico 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, to the Gulf of Mexico. As such, crossing the river was the escape route used by some Texas slaves 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. 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.

In the summer of 2001, a 328-foot (100 m) wide sandbar 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

View of the Rio Grande from Overlook Park, White Rock, New Mexico.

Further information: Rio Grande Project

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, 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, Elephant Butte Dam, Caballo Dam, Amistad Dam, Falcon Dam, Anzalduas Dam, and Retamal Dam. In southern New Mexico and the upper portion of the Texas border segment, the river's discharge dwindles. Diversions, mainly for agricultural irrigation, have increased the natural decrease in flow such that by the time the river reaches Presidio, Texas, there is little or no water. Below Presidio the Rio Conchos restores the flow of water. Near Presidio the river's discharge is frequently zero. Its average discharge is 178 cubic feet per second (5 m³/s), down from 945 cubic feet per second (27 m³/s) at Elephant Butte Dam. Supplemented by other tributaries the Rio Grande's discharge increases to its maximum annual average of 3,504 cubic feet per second (99 m³/s) near Rio Grande City, Texas. Large diversions for irrigation below Rio Grande City reduce the river's average flow to 889 cubic feet per second (25 m³/s) at Brownsville and Matamoros.

Crossings

Main article: List of crossings of the Rio Grande

The major international border crossings along the river are at Ciudad Juárez and El Paso; Presidio, Texas, and Ojinaga, Chihuahua; Laredo, Texas, and Nuevo Laredo, Tamaulipas; McAllen, Texas, and Reynosa, Tamaulipas; and Brownsville, Texas, and Matamoros, Tamaulipas. Other notable border towns are the Texas/Coahuila pairings of Del Rio–Ciudad Acuña and Eagle Pass–Piedras Negras.

Names and pronunciation

The Rio Grande (Rio del Norte) as mapped in 1718 by Guillaume de L'Isle.

Río Grande is Spanish for "Big River" and Río Grande del Norte means "Great River of the North". In English, 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 Río Bravo del Norte, bravo meaning (among other things) "furious" or "agitated".

Historically, the Pueblo and Navajo peoples also had names for the Rio Grande/Rio Bravo:

• mets'ichi chena, Keresan, "Big River"
• posoge, Tewa, "Big River"
• paslápaane, Tiwa, "Big River"
• hañapakwa, Towa, "Great Waters"

The four Pueblo names likely predated the Spanish entrada by several centuries.

• Tó Baʼáadi, Navajo, "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 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 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 to the sea.

By 1602, Río Bravo had become the standard Spanish name for the lower river, below its confluence with the Rio Conchos.

Tributaries

Main article: List of tributaries of the Rio Grande

The largest tributary of the Rio Grande by discharge is the Rio Conchos, which contributes almost twice as much water as any other. In terms of drainage basin size the Pecos River is the largest.

Tributary	Average discharge		Drainage basin
	cu ft/s	m3/s	sq mi	km2
San Juan River	368	10	12,950	33,500
Rio Alamo	130	3.68	1,675	4,340
Rio Salado	354	10.0	23,323	60,400
Rio San Rodrigo	130	3.68	1,050	2,720
Devils River	362	10.3	137	355
Pecos River	265	7.50	44,402	115,000
Rio Conchos	848	24.0	26,400	68,400
Rio Puerco	39.5	1.1	7,350	19,000
Jemez River	59.5	1.68	1,038	2,688
Santa Fe River	10.9	0.31	231	598.3
Rio Chama	571	16.2	3,144	8,143
Conejos River	176	4.98	887	2,297

See also

Rio Bravo, Texas Rio Grande border disputes List of crossings of the Rio Grande List of Colorado rivers List of international border rivers List of longest main-stem rivers in the United States List of longest rivers of Mexico List of New Mexico rivers

List of Texas rivers Rio Grande Wild and Scenic River Rio Grande Valley Rio Grande Gorge Rio Grande Trail

Rio Grande Project Big Bend National Park Chihuahuan Desert Trans-Pecos West 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
• Lea, Tom (1957). The King Ranch. Little Brown & Co. ISBN 9780316517454. 
• Kelley, Pat (1986). River of Lost Dreams: Navigation on the Rio Grande. University of Nebraska Press. ISBN 9780803227125. 
• Caleb Coker, ed. (1992). The News from Brownsville: Helen Chapman's Letters from the Texas Military Frontier, 1848-1852. Texas State Historical Association. ISBN 0876111150. 
• Kearney, Milo; Anthony K. Knopp (1995). Boom and Bust: The Historical Cycles of Matamoros and Brownsville. Eakin Press. ISBN 9780890158159. 

External links

• Border Stories: the only hand pulled ferry on the Rio Grande (video)
• 1854 map of Rio Grande entrance (hosted by the Portal to Texas History).
• Rio Grande Cam - in Mission Texas. Mexico is on the left and the US is on the right.