Will the Great Black Hawk Gypsum Sinkhole eat Interstate 90? Anything could happen, suggests Dr. Mohammadhossein Sadeghiamirshahadi of Montana Technical University: An abandoned gypsum mine…
Notes from a South Dakota Ex-Pat
Will the Great Black Hawk Gypsum Sinkhole eat Interstate 90? Anything could happen, suggests Dr. Mohammadhossein Sadeghiamirshahadi of Montana Technical University: An abandoned gypsum mine…