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.
Amargosa River The Amargosa River is an intermittent waterway, 185 miles (298 km) long, in southern Nevada and eastern California in the United States. It drains a high desert region, the Amargosa Valley in the Amargosa Desert northwest of Las Vegas, into the Mojave Desert, and finally into Death Valley where it disappears into the ground aquifer. Except for a small portion of its route in the Amargosa Canyon in California and a small portion at Beatty, Nevada, the river flows above ground only after a rare rainstorm washes the region. A 26-mile (42 km) stretch of the river between Shoshone and Dumont Dunes is protected as a National Wild and Scenic River. At the south end of Tecopa Valley the Amargosa River Natural Area protects the habitat.