San Luis: Twin Cities on the Colorado

San Luis, Arizona, faces its Mexican counterpart San Luis Rio Colorado, Sonora, across a border that crosses the lower Colorado River delta. Together they form a binational community of roughly five hundred thousand people. The US side incorporated as a city in nineteen seventy-nine and is the youngest city in Yuma County, but the crossing here has been active since the early twentieth century when agricultural development on both sides of the border drew workers to the irrigation-fed fields of the Yuma Desert.

The San Luis port of entry is an important commercial crossing on the Arizona-Mexico border. Fresh produce grown in the neighboring Mexicali Valley, one of the most productive agricultural regions in Mexico, passes through this port by the truck load each day, bound for grocery stores across the western United States. The Colorado River once flowed strong past this point. Today the river rarely reaches the sea at all, its water allocated entirely upstream before it can complete the journey.