First Interstate Bank today officially opens the former Great Western Bank branches in Iowa and seven other Midwest states as First Interstate Bank branches. First Interstate BancSystem Inc. completed its merger with Great Western Bancorp Inc. on Feb. 1, with the combined bank providing access to more than 320 branches across 14 states. “It’s an exciting day for our clients, our employees, and the communities where we live and work,” Kevin Riley, president and CEO of First Interstate BancSystem, said in a press release. “The same Great Western bankers you’ve come to know and trust have opened their doors today as First Interstate. New clients can expect to receive the same high level of service with access to additional products, digital tools, and convenience services not previously available at Great Western.” Before the merger, Sioux Falls, S.D.-based Great Western had operated 48 branches or ATMs in Iowa. First Interstate, based in Billings, Mont., on Friday closed 10 former Great Western branches in three states as a result of the merger, including one branch in Missouri Valley and another in Eldora. The approximately $1.7 billion merger transaction was made through a common stock issuance. First Interstate Bank’s assets increased $13.49 billion, or 68.6%, to $33.16 billion as of March 31, primarily as a result of assets acquired from Great Western Bank.