Theses and Dissertations - UTB/UTPA

Date of Award


Document Type


Degree Name

Master of Arts (MA)



First Advisor

Dr. James Irby

Second Advisor

Dr. David Vassberg

Third Advisor

Dr. Hubert J. Miller


In 1906, the American Rio Grande Land and Irrigation Company diverted the Rio Grande, creating a U.S. enclave called El Horcon in Mexican territory. For 71 years, this tract of land was tilled by local farmers, only gaining attention towards the end of its existence. Despite causing minimal issues, potential conflicts persisted until its cession to Mexico in 1977. Initially, U.S. government action in 1911 rectified immediate damage to ranchers affected by the diversion. However, ambiguity in sovereignty led to legal disputes and unauthorized cross-border activities. El Horcon's unique status allowed farmers to violate both U.S. and Mexican laws, highlighting the need for an international port of entry and work permits, which were never established.

Rio Rico, a town established in 1928 near El Horcon, operated without knowledge of its partial location in the U.S., avoiding significant economic or criminal issues. When Mexico built flood control levees, it moved part of Rio Rico onto U.S. soil, causing jurisdictional confusion and unchallenged exercise of Mexican authority in the U.S. From 1945 to 1977, Mexican officials administered the town, exacerbating legal ambiguities.

El Horcon's existence, largely unnoticed due to its minimal value and disturbance, underscores the importance of proactive boundary management. The experience demonstrates that unresolved sovereignty issues, like those highlighted by Homero Cantu's citizenship battle, can lead to prolonged legal and administrative complications. This case suggests the necessity for timely bilateral resolutions to prevent future problems stemming from border alterations.


Copyright 1983 Stephen Jay Phelps.

Granting Institution

Pan American University