Environmental issues at the U.S.–Mexico border have been approached in a fragmented way and considered of minor political interest; even though they have been addressed in treaties and agreements, regional environmental pollution persists. One may ask what sort of measures should be taken to address the complex and long-term environmental problems in the U.S.–Mexico border region. To answer this question, an environmental cross-border governance proposal was evaluated by applying Qualitative Analysis of Textual Data to the text of Chapter 24 of the USMCA treaty. The results indicated that the environmental policies concerning the border region still lack a coherent systemic approach, and hence will lead to inefficiency. Territorial development is heavily dependent on national environmental governance and priorities; however, environmental issues should be understood in an integral, complex and deeply entangled way if they are to be effectively addressed. Otherwise, environmental degradation is likely to expand due to population growth and events associated with climate change.