Yellowstone Park is known with geysers. One of the most famous geysers is Old Faithful. It is a wonderful geyser. It erupts about every hour, winter or summer, day or night. Once every hour, Old Faithful sends a column of hot water into the air. It is over 100 feet high.
There are about 200 geysers in Yellowstone Park. The Giant Geyser throws water about 175 feet into the air, but it does not erupt regularly. No one knows when it will erupt.
Niagara Falls (552)
Niagara Falls is the best known natural wonder in the USA. It is situated between New York and Chicago. Niagara is an Indian word which means "roaring waters". Indeed the roar of the water can be heard at a distance of 25 kilometres. A mass of water is felling over a cliff 90 feet high (27 metres) with a terrible noise. Niagara has very great power. It can move big rocks and throw them into the waters. Niagara Falls is beautiful and all time changing! Many great writers tried to describe it. The Niagara River gives electric power too. More than a million horse power is produced now at Niagara for local use and is sent to cities and towns in New York State and to Canada.