Texas claims nine Rio Grande islands for border patrols

Texas has taken control of nine islands in the Rio Grande between Laredo and McAllen, with Land Commissioner Dawn Buckingham authorizing the National Guard to access, clear and patrol them. Mexico's foreign ministry answered by invoking the 1970 Boundary Treaty, under which the international boundary is determined by the binational commission the two countries created for exactly that purpose.

The move follows a request from US Customs and Border Protection concerning 28 river islands previously considered unclaimed or of undetermined ownership. The Texas General Land Office, working from historical maps, topographic surveys and aerial photographs, determined that it could access the islands, clear them and patrol them — territory its own statement described as uncertain "whether they belonged to the state of Texas or the federal government or Mexico." The office's stated problem was that unclear title had hampered access by state law enforcement and border security operations.

In a letter dated October 26 to Major General Thomas Suelzer, head of the Texas Military Department, and Colonel Freeman Martin of the Department of Public Safety, Buckingham wrote that the effort builds on the GLO's work to "establish ownership of Rio Grande islands and ensure law enforcement can access state-owned property." The same letter states: "While we have not confirmed criminal activity on these additional islands, past experience has shown how border islands can be exploited by cartels and smugglers."

Mexico reads the same islands through the treaty signed in 1970 to resolve border disputes and regulate changes in the river's channels. The border follows the middle of the river's normal channel; ownership of islands shifts with the channel; and Article IV requires that any work on the islands receive "consideration and approval by both sections" of the International Boundary and Water Commission. Determining the international boundary, the foreign ministry says, is solely that commission's responsibility.

Rosario Sánchez, director of the nonprofit Binational Waters, which works on water resources along the border, told El País that decisions about federal boundaries and waters "are not a state" matter. Border security has been a main pillar of Donald Trump's second term, and the request the GLO cites came from federal Customs and Border Protection — while the ownership determination was the state's own work. Neither section of the International Boundary and Water Commission, the body Mexico says alone determines where the border runs, had responded to El País's questions by publication time.