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
Lock and Dam No. 7 roller gates and 11 tainter gates, a segment of earth embankment long from the dam to French Island separated by a concrete spillway long, and another embankment long from French Island to Onalaska which has a concrete spillway long. The lock is wide by long. The lock and dam is one of the most visited because of its proximity to Interstate 90, and is clearly visible to travelers crossing the I-90 Mississippi River Bridge. Lock and Dam No. 7 Lock and Dam No. 7 is a lock and dam located on the Upper Mississippi River at river mile 702.5 near