The Valley is now home to about a million people, and there are a couple of big development projects in the works.
Plans call for a commercial spaceport near Brownsville. Also the University of Texas is creating a new medical school.
But when it comes to moving goods and people, local leaders were faced with a big problem.
"We were one of the areas in the country that didn't have a major interstate going through. We had no interstate. There was nothing south of I-10."
That's Julian Alvarez with the Rio Grande Valley Partnership. It's an organization that promotes economic growth in the region.
Alvarez is applauding the new I-69 designation on two existing highways in the Valley.
Signs have gone up on a 53-mile stretch of US 77 near the U.S./Mexico border. There are also signs on a 14-mile section of U.S. 281 from ED-din-berg to Pharr.
"You know when folks are looking at bringing in industry to south Texas, that's one of the first things they ask, is there a major interstate that goes through our ports of entry."
The long-term plan for I-69 is to create an interstate highway through the central part of the country that links the Canadian and Mexican borders.
Here in the Houston area, drivers are seeing the I-69 shields along sections of U.S. 59. The newest signs are going up along a 28-mile segment from I-610 west to Rosenberg.