21. Great Falls
Great Falls, Montana - Where the Lewis and Clark expedition had a major
headache and some very small Casino's
The Missouri river has 5 falls in this area and the Lewis and Clark expedition
(google it) had to drag their boats around them.
http://www.lewis-clark.org/
It took them 2 years to cross the continent with some help from the natives only
to find that there was no water route across the country, a monumental
achievement and then they had to go back.