The International Boundary and Water Commission (IBWC) is the binational agency that defines the U.S.–Mexico border and can be called to review disputes or questions about the border location.
June 01, 2025
high
institutional
IBWC administers and adjudicates technical matters regarding the U.S.–Mexico boundary and water treaties.
Shifting riverbeds, such as sections of the Rio Grande, can complicate precise determination of international land borders when rivers are used as boundary markers.
June 01, 2025
high
geographic
Natural changes in river courses can create uncertainty about the exact location of river-defined borders.