Drowning the Hidatsa
The Hidatsa and Mandan tribes helped Lewis and Clark as they trekked west. Eventually, smallpox destroyed most of the tribes populations. They were allocated a reservation which was slowly stolen away. In 1948, they were forced out of their fertile river plain in order to make a dam. This site has a tragic photo of coucnil chairman of the tribes weeping as the secretary of the interior signs away his people's land. I ended up at this story because I like the earth lodges of the people. But many of these historic sites were flooded by this dam.