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 Quartette Landing and Eldorado Canyon in Nevada, the landings and the mills there were abandoned. The town of Nelson was founded near the head of the canyon nearest the road to the railroad, the post office of Eldorado was closed in August 31, 1907 and moved to Nelson. In 1906, Santa Fé railroad built the Barnwell and Searchlight Railway to the west to tie Searchlight to its subsidiary California Eastern Railway at Barnwell, California. Also in 1905, the Arizona and California Railroad bridged the Colorado River at Parker, Arizona, cutting in half the last profitable section of the river for