First Interstate BancSystem, Inc. (“FIBK”) announced that it expects Scott Erkonen and Karlyn Knieriem to join the FIBK executive team upon the closing of the previously announced merger of Great Western Bancorp, Inc. (“GWB”) into FIBK. At the effective time of the merger, Mr. Erkonen will serve as the Chief Information Officer and Ms. Knieriem will serve as the Chief Risk Officer. As previously announced, the merger of GWB into FIBK and the transaction is expected to close on or around February 1, 2022, subject to customary closing conditions set forth in the merger agreement between FIBK and GWB.