They have 12 open pit mines in Wyomning, and they keep moving one highway for the mines. They also have to replace the earth, the way they found it, minus the coal of course.
The theory is that diamonds are formed inside the throat of really deep volcanos. The odd thing is, most of the diamond mines are in flat places, but with a long history of vulcanism.
This being Russia, they don't have to put it back the way it was.
It is impossible to get an idea of the scale of the thing