Nearly two-thirds of the border follows the Rio Grande river. And rivers? They have a mind of their own. The Rio Grande meanders so much that the actual borderline can shift by a few feet every year due to erosion and sediment.
This means the border is alive. Imagine having a property line that moves every time it rains. You’d need a surveyor on speed dial—and a good sense of humor.
In fact, a 1970 treaty between the US and Mexico basically said, “Okay, the river moves, but the border stays put.” So now the border is “fixed” even when the river throws a tantrum. Clever, right?
From the Pacific to the Gulf
The border starts at the Pacific Ocean, right where San Diego, California, meets Tijuana, Mexico. From there, it heads east, cutting through deserts, mountains, and cities like El Paso and Ciudad Juárez.
It ends at the Gulf of Mexico, near Brownsville, Texas, and Matamoros. Fun fact: that last stretch is just a line drawn in the sand—literally. No fence, no wall, just a beach where people wave at each other.
If you walked the entire border without stopping (and had amazing calf muscles), it would take you about 550 hours. That’s 23 straight days of hiking. Better pack snacks and a very good playlist.
