Great Western Bancorp, Inc. Information Request Form

Levi & Korsinsky, LLP has commenced an investigation into the fairness of the merger of Great Western Bancorp, Inc. (NYSE: GWB) (“GWB” of the “Company”) with First Interstate BancSystem, Inc. (“FIBK”). Under the terms of the merger, GWB shareholders will receive .8425 shares of FIBK Class A common stock for each GWB share they own. Following completion of the transaction, GWB shareholders will collectively own 43% of the combined company.

The GWB merger investigation concerns whether the Board of GWB has harmed stockholders by agreeing to enter into this transaction and whether all material facts have been properly disclosed to stockholders.