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
Milltown Dam (St. Croix River) Milltown Dam (St. Croix River) The Milltown Dam is a hydroelectric dam built on the St. Croix River between St. Stephen, New Brunswick, Canada and Calais, Maine, USA, and operated by NB Power. Its power house has a capacity of 4 megawatts with its 7 turbines. Built in 1881 and modernised in the early-1900s, it is the oldest hydroelectric dam in Canada, as well as the first hydroelectric facility built by NB Power. Electricity generated by the Milltown Dam is also exported to the United States, connected to a 69,000 volt transmission circuit owned by the Eastern Maine Electric Cooperative,