What was the original name of the dam that serves as the northern boundary of the Topock Marsh?
Hoover Dam Hoover Dam, originally known as Boulder Dam from 1933 to 1947, when it was officially renamed Hoover Dam by a joint resolution of Congress, is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the U.S. states of Nevada and Arizona. It was constructed between 1931 and 1936 during the Great Depression and was dedicated on September 30, 1935, by President Franklin D. Roosevelt. Its construction was the result of a massive effort involving thousands of workers, and cost over one hundred lives. The dam was named after President Herbert Hoover.
River Perry, Shropshire The River Perry is a river in Shropshire, England. It rises near Oswestry and flows south to meet the River Severn above Shrewsbury. Along its 24 mi length, its level drops by some 320 feet (95 m). The channel has been heavily engineered, both to enable water mills to be powered by it, and to improve the drainage of the surrounding land. There were at least seven corn in the 1880s, and the last one remained operational until 1966. The middle section of the river crosses Baggy Moor, where major improvements were made in 1777 to drain the moor. The scheme was one of the largest to enclose and improve land in North Shropshire, and the quality of the reclaimed land justified the high cost. A section of the river bed was lowered in the 1980s, to continue the process.