The river was relocated in two reaches by the construction of a new channel in one reach and in the other. The relocated channel was aligned in the reach above
Presidio-
Ojinaga so as to transfer from north to the south side of the river and in the second reach downstream from the two cities so as to transfer from the south to the north side a net area of . It is an earth channel with dimensions patterned after the natural channel. The United States acquired of American agricultural land that was used for the transfer of lands to Mexico and for half of the river relocation. Also, the channel of the Rio Grande in the
Hidalgo–
Reynosa area was relocated to transfer from Mexico to the United States by constructing a new flood control channel. This transfer was made in exchange for the transfer from the United States to Mexico of other land, including five parcels near Presidio, the
Horcón Tract (after 1906 located south of the Rio Grande), and
Beaver Island (La Isla de Morteritos), located in the river south of
Roma, Texas, comprising in total. This provision transferred to Mexico the portion of the town of
Río Rico, Tamaulipas, located within the Horcón Tract. The cost of the two relocations was shared equally by the two governments, with the United States performing the greater part of the work required in the Presidio-Ojinaga area, and Mexico performing the work required in the Hidalgo-Reynosa area and a small part of the work required in the Presidio-Ojinaga area. On November 24, 2009, the U.S. ceded six islands in the Rio Grande to Mexico. At the same time, Mexico ceded three islands and two
bancos to the U.S. This transfer, which had been pending for 20 years, was the first application of Article III of the 1970 Boundary Treaty. ==See also==