Hypothetical Scenario

Hypothetical Scenario   (06/10/2011, 8:53 PM)

I need the measurment & if possible a Map or geological reference to the measurment?
20sq.mile x 20 sq.mile x 541.338582675 sq. feet, excavation type pit.

any reference of this measurment even on a map of any country would work, prefer a Reference on a 48 state U.S. Map. thank you for your help