Where Does the Rio Grande River Start and End

About 3 million years ago, water draining from the San Juan Mountains of Colorado began carving the river that dissects New Mexico and, eventually, the west and southwest boundary of Texas and the Texas-Mexico border, before emptying into the Gulf of Mexico and this would become The Rio Grande River. Where Does the Rio Grande River Start and End?

The Upper headwaters of the Rio Grande River originates in Colorado high in the San Juan Mountains & the Continental Divide flowing south through the San Luis Valley in Colorado, then to Albuquerque & Las Cruces, NM it continues south across the Texan border & ends at the mouth of the Gulf of Mexico.

Probably the first Europeans to see any part of the Rio Grande were those of a Spanish expedition sent out in 1519 to survey the coast of the Gulf of Mexico. Another expedition led by the explorer Francisco Vázquez de Coronado in 1540 to locate rumored rich cities to the north of Mexico resulted in the discovery of various Pueblo Indian communities and explorations in the middle of the Rio Grande and upper Pecos areas.


Where Does the Rio Grande River Start


Rio Grande Headwaters | Photo
    Headwaters of the Rio Grande

The headwaters of the Rio Grande River originates in Colorado with two main source points found in the San Juan Mountains that are 10,000 to 14,000 ft. high and the Continental Divide. This region of Colorado feeding the Rio Grande receives up to 350 inches of snow a year added with the average rainfall producing a huge water source tumbling down from higher to lower elevations sustaining the river system year after year. 

Another primary source is Canby Mountain, with its second, more distant source, being Pole Creek. The River flows south through the San Luis Valley in Colorado, then on to Albuquerque and Las Cruces in New Mexico.

The principal tributaries making up the flow of the Rio Grande river are the Pecos, Devils, Chama, and Puerco rivers in the United States and the Conchos, Salado, and San Juan in Mexico all feeding the Rio Grande.

The peak flow of the river happens in the upper regions in May and June because of melting snow and thunderstorms and the lower portion commonly experiences its highest water levels in June or September because of the occurrence of summer thunderstorms. The River flows south through the San Luis Valley in Colorado, then on to Albuquerque and Las Cruces in New Mexico.

The Rio Grande drainage basin (watershed) has an area of 182,200 square miles however, the endorheic basins (An endorheic basin is a drainage basin that normally retains water and allows no outflow) that are adjacent to and within the greater drainage basin of the Rio Grande increase the total drainage-basin area to 336,000 square miles 

Where Does the Rio Grande River End


As it continues south across the Texan border passing places like El Paso, Presidio, Del Rio, Eagle Pass, Laredo, Rio Grande City, McAllen, and Brownsville the Rio Grande River concludes right on the shores at the mouth of the Gulf of Mexico.

Shortly before entering the Gulf Coastal Plain, The Rio Grande joins the Pecos River that originates in north-central New Mexico and flows into Texas, emptying into the Rio Grande. Along with the remainder of its course, the river wanders sluggishly across the Gulf Coastal Plain to end in a fertile delta where it joins the Gulf of Mexico.

The Rio Grande river system only draws from 11% of the continental United States, with much of that being drought-prone land. That vulnerability is compounded by scores of dams and irrigation diversions, which have left significant portions of the river dry in recent years. In recent years the Rio Grande river failed to reach its final destination the Gulf of Mexico for the first time. Will Rogers once described the Rio Grande as “the only river I know of that is in need of irrigating,”


How Long is the Rio Grande River


The Rio Grande River starts in Southern Colorado near Creede as a clear, snow-fed mountain stream more than 12,000 feet above sea level in the San Juan Mountains and the Continental Divide. The Rio Grande descends across steppes and deserts, watering rich agricultural regions as it flows on its way almost 1900 miles to the Gulf of Mexico.

It is the 3rd longest river system in the United States and in the top 20th longest in the world.  It reaches peak flow from snowmelt like most mountains in the US and has many problems that have developed over the years. Because of both drought and overuse, the Rio Grande is considered threatened by Climate Change like most rivers in the southwestern United States.

The Rio Grande was named “El Rio Bravo del Norte,” or “The Fierce River of the North,” by Spanish explorers in the 1500s. It is still known as “Rio Bravo” in Mexico. It is considered one of the most principal rivers in the southwest region of the country. Translated meaning “The Big River” The Rio Grande flows through 3 US states and 4 Mexican states. 

The Rio Grande flows first to southeast and south for 175 miles (280 km) in Colorado, southerly for about 470 miles across New Mexico, and southeasterly for about 1,240 miles between Texas and the Mexican states of Chihuahua, Coahuila, Nuevo León, and Tamaulipas and concludes at the mouth of the Gulf of Mexico.

After traversing the entire length of New Mexico, the Rio Grande becomes the Mexico–United States border, between the U.S. state of Texas and the northern Mexican states of Chihuahua and Coahuila, Nuevo León, and Tamaulipas; a short segment of the Rio Grande is actually a state-boundary between the U.S. states of New Mexico and Texas.

Rio Grande River Map


Introduction | WildEarth Guardians Upper Rio Grande River

One of the most important tributaries in the Rio Grande River system is the Chama starts as a high-altitude stream moving through the thick wilderness of Colorado and New Mexico. Below the Chama river, the Rio Grande meets up with beautiful Heron Lake located in northern New Mexico which is about 4 miles long and 3 miles wide and lies at an elevation of 7000 ft.

Heron Lake State Park is a scenic lake area that is ideal for kayaking, sailing, and windsurfing, as well as fishing for record-size trout and ice fishing. After traveling through Colorado and northern New Mexico the Rio Grande finds the Rio Grande State Park near the town of Pillar.

The river widens as it passes through 800-foot chasms of the Rio Grande Gorge, a wild and remote area of northern New Mexico. In 1968, the Rio Grande and Red Rivers were among the first eight rivers Congress designated into the National Wild and Scenic River System to protect outstanding resource values.

The Rio Grande continues to run south after Albuquerque NM to Belin, New Mexico through agricultural farmlands is heavy. This is where the Rio Grande starts to dry up being diverted for irrigation and is reduced to no more than a trickle. South of Belin, the flow increases as the river runs southward to Las Cruces but the banks of the river are lined with silt.

Lower Rio Grande River

After hitting the 242,555 acres park Rio Grande del Norte National Monument that lies north and south of Taos, New Mexico. The Box Canyons offer dramatic wilderness and an important bird sanctuary surrounding some of the best-class whitewater in the West for skilled paddlers, establishing an outdoor recreational mecca that extends downstream along 74 miles of Wild & Scenic River. It’s a solid 600 miles between rapids until the river reaches its lower Wild & Scenic designation surrounding Big Bend National Park along the Texas border with Mexico




Rio Grande Border


A sign is posted near the US and Mexico border warning drivers of immigrants crossing the freeway in San Ysidro, CA in 2006, just before the signing of the Secure Fence Act. (Credit: Hector Mata/AFP/Getty Images)
US and Mexico border warning drivers of immigrants crossing the freeway

The Rio Grande serves as the natural border between the United States and Mexico. It shares a border with states in Mexico such as Tamaulipas, Nuevo León, Coahuila, and Chihuahua. Texas and Mexico also disagreed with the location of the border.

Texas claimed its border with Mexico was the Rio Grande, while Mexico claimed its border with Texas was at the Nueces River. This dispute over the Texas-Mexico border caused more problems when the U.S. annexed Texas in 1845.

It was then that the U.S. declared war against Mexico a year later, which started the Mexican-American War.

The border between the United States and Mexico stretches for nearly 2,000 miles from the Gulf of Mexico to the Pacific Ocean and touches the states of California, Arizona, New Mexico, and Texas. After a series of bloody battles and sieges, American forces captured the Mexican capital in September 1847.

The Rio Grande runs along 1,254 miles of the border, but west of El Paso, Texas, the boundary lacks a natural geographic barrier except for a small stretch along the Colorado River.

Approximately 700 miles of barbed wire, chain link, post-and-rail, fencing, and wire mesh fencing have been erected along the U.S.-Mexico border. The U.S. Border Patrol also utilizes thousands of cameras and underground sensors as well as aircraft, drones, and boats to monitor the boundary.




Where Does the Missouri River Begin and End

Read about more great American rivers here on MyWaterEarth&Sky like this article on The Missouri River-Recognized as America’s longest river, the Missouri River is known as the “Center of Life” in the Great Plains. From agriculture to food, this winding waterway plays a major role …….Continue reading



  JimGalloway Author/Editor




References: Undercover Colorado-The Rio Grande River

Recreation gov.com- Heron State Park New Mexico




Recent Posts