International Boundary and Water Commission in the context of "Texas-Mexico border"

The international boundary separating Mexico and United States extends from the Pacific Ocean to the Gulf of Mexico. The border traverses a variety of terrains, ranging from urban areas to deserts. It is the most frequently crossed border in the world, with approximately 350 million documented crossings annually. Illegal crossing of the border to enter the United States has caused the Mexico–United States border crisis. It is one of two international borders that the United States has, the other being the northern Canada–United States border; Mexico has two other borders: with Belize and with Guatemala.

Four American Sun Belt states border Mexico: California, Arizona, New Mexico and Texas. One definition of Northern Mexico includes only the six Mexican states that border the U.S.: Baja California, Chihuahua, Coahuila, Nuevo León, Sonora and Tamaulipas. The total length of the continental border is 3,145 kilometers (1,954 miles). From the Gulf of Mexico, it follows the course of the Rio Grande (Río Bravo del Norte) to the border crossing at Ciudad Juárez, Chihuahua, and El Paso, Texas. Westward from El Paso–Juárez, it crosses vast tracts of the Chihuahuan and Sonoran deserts to the Colorado River Delta and San Diego–Tijuana, before reaching the Pacific Ocean.

The international border between Guatemala and Mexico measures 871 km (541 mi). It runs between north and west Guatemala (the Guatemalan departments of San Marcos, Huehuetenango, El Quiché and El Petén) and the Mexican states of Campeche, Tabasco and Chiapas. The border includes stretches of the Usumacinta River, the Salinas River, and the Suchiate River.

Geopolitically, this border represents much of the western and northern boundary of the region of Central America within North America. It is across this border that most of the commerce between Mexico and Guatemala and the rest of Central America takes place.

The vast majority of the current border was decided after the Mexican–American War (1846–1848). Most of the border is situated along the Rio Grande River, which marks the boundary between Texas and northeastern Mexico. To the left lies San Diego, California, and on the right is Tijuana, Baja California. The building in the foreground on the San Diego side is a sewage treatment plant built to clean the Tijuana River.

The international boundary separating Mexico and United States extends from the Pacific Ocean to the Gulf of Mexico. The border traverses a variety of terrains, ranging from urban areas to deserts. It is the most frequently crossed border in the world, with approximately 350 million documented crossings annually. Illegal crossing of the border to enter the United States has caused the Mexico–United States border crisis. It is one of two international borders that the United States has, the other being the northern Canada–United States border; Mexico has two other borders: with Belize and with Guatemala.

The Treaty on (relating to the) utilization of waters of the Colorado and Tijuana Rivers and of the Rio Grande or the 1944 Water Treaty is a cooperative agreement between the United States and Mexico defining the allocation of Rio Grande water to the U.S. and Colorado River water to Mexico. The agreement was signed in 1944 as an instrument of the two countries' International Boundary and Water Commission (IBWC). The agreement is a subject to frequent changes, delivered through the so-called "Minute Process".

The agreement has been used as a tool for peaceful resolution of transborder water management issues, but some tensions have since arose in the 21st century regarding Mexico's water deliveries to the U.S., which have reportedly become inconsistent and insufficient since the 1990s.