Río Rico is a village located along the Rio Grande in the Mexican state of Tamaulipas.

The international border was moved under the terms of the Boundary Treaty of 1970, placing the tract and the village in Mexico, effective in 1977.

[2][5] However, the former riverbed dried up rather than forming an oxbow lake, and the company never put up border markers,[4] leaving the tract barely distinguishable from the adjacent Mexican territory.

[6] In 1929, the Mexican village of Río Rico was founded near the tract, and as the Rio Grande changed its course after floods, the settlement progressively moved into it.

The Boundary Treaty of 1970 provided for the Horcón Tract to become part of Mexico upon the completion of two new flood control projects.