Course of the Colorado River into the Virgin River, which ran southward through what is now Overton Arm to join the Colorado River near the now-ghost town of St. Thomas, Nevada. At Hoover Dam, the Colorado turns due south through Black Canyon, a direction it will follow for the remainder of its course to the Gulf of California. It passes under the Mike O'Callaghan–Pat Tillman Memorial Bridge (Hoover Dam Bypass), the highest concrete arch bridge in the world, carrying U.S. Route 93 at a height of above the Colorado River. At the end of Black Canyon the Colorado widens into Lake Mohave, created by the
Karun-4 Dam Karun-4 Dam The Karun-4 Dam is an arch dam on the Karun River located at 180 km southwest of Shahr-e-Kord in the province of Chaharmahal and Bakhtiari, Iran. The Karun has the highest discharge of all the Iranian rivers. Its construction is aimed at electric power supply of 2107 million kWh annually and controlling floods in the upper Karun. The dam is a concrete double curvature arch-type and high from the foundation. The arch dam design is an ideal one for a dam built in a narrow, rocky gorge to hold back water in a reservoir. The dam is curved.