The Chamizal dispute was caused by a shift in which one of the principal rivers in the southwest United States and northern Mexico?
Rio Grande The Rio Grande ( or ; Spanish: Río Bravo del Norte , ] or simply Río Bravo) is one of the principal rivers in the southwest United States and northern Mexico (the other being the Colorado River). The Rio Grande begins in south-central Colorado in the United States and flows to the Gulf of Mexico. Along the way, it forms part of the Mexico–United States border. According to the International Boundary and Water Commission, its total length was 1896 mi in the late 1980s, though course shifts occasionally result in length changes. Depending on how it is measured, the Rio Grande is either the fourth- or fifth-longest river system in North America.
Nevada Basin The Nevada Basin is the Great Basin area surrounded by river basins and, to the east, the Great Salt Lake basin (Pleistocene Lake Bonneville basin). The bounding river basins include those of the following (clockwise from south-southeast): Sevier River, Muddy River (Meadow Valley Wash, White River), Las Vegas Wash, Colorado River, Mojave River, Amargosa River, Owens River, Lake Lahontan basin (Walker River, Carson River, Humboldt River, Reese River), and Snake River. The 1850 diagonal California state lines with the Utah Territory & New Mexico Territory are along the general direction of the Nevada Basin's southwest drainage divide (rim), while the north-to-south rim on the east is through the area of the three meridians (1861, 1862, & current 1864) used for the Nevada-Utah state line.