Its territorial boundaries are Cameron and Willacy counties to the east, Kenedy and Brooks counties to the north, Starr County to the West and the channel of the Rio Grande to the South, which also serves as the international border with Mexico.
Sus límites territoriales son al este con los condados de Cameron y Willacy, al norte con Brooks y Kenedy, al poniente con Starr y al sur con el cauce del río Grande, mismo que le sirve de frontera internacional con México.