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
Steamboats of the Colorado River Steamboats of the Colorado River Steamboats on the Colorado River operated from the river mouth at the Colorado River Delta on the Gulf of California in Mexico, up to the Virgin River on the Lower Colorado River Valley in the Southwestern United States from 1852 until 1909, when the construction of the Laguna Dam was completed. The shallow draft paddle steamers were found to be the most economical way to ship goods between the Pacific Ocean ports and settlements and mines along the lower river, putting in at landings in Sonora state, Baja California Territory, California state, Arizona Territory, New