U.S. – Mexico border cities, from San Diego-Tijuana in the west to Brownsville-Matamoros in the east (14 major cross-border cities).
Cities with fewer than 15,000 inhabitants were omitted:
– Andrade, CA / Los Algodones, B.C.
– Lukeville, AZ / Sonoyta, Son.
– Sasabe, AZ / Altar, Son.
– Naco, AZ / Naco, Son.
– Columbus, NM / Palomas, Chih.