A: There are four types of hiatal hernias. Most hiatal hernias are called type I or âsliding hernias,â where the stomach intermittently slides up into the chest through a small opening in the diaphragm. Sliding hernias are very common, and most donât require surgery.: There are four types of hiatal hernias. Most hiatal hernias are called type I or âsliding hernias,â where the stomach intermittently slides up into the chest through a small opening in the diaphragm. Sliding hernias are very common, and most donât require surgery.
Shasta Dam, which was completed in 1945 on the upper Sacramento River northwest of Redding, is the second-largest reservoir run by the Bureau of Reclamation in the country, behind Grand Coulee Dam in Washington.
Hoover Dam. Hoover Dam, formerly called Boulder Dam, dam in Black Canyon on the Colorado River, at the Arizona-Nevada border, U.S. Constructed between 1930 and 1936, it is the highest concrete arch dam in the United States. It impounds Lake Mead, which extends for 115 miles (185 km) upstream and is one of the largest manmade lakes in the world.