Upon completion of this merger, First Interstate will have total assets of approximately $8.2 billion and gain the #1 deposit market share in the state of Montana. First Interstate expects the transaction to be immediately accretive to earnings per share. The transaction, unanimously approved by the boards of directors of both companies, is subject to regulatory approval and approval by the shareholders of Mountain West. Completion of the acquisition is expected by mid-2014.First Interstate management will review additional information regarding the transaction in a conference call beginning at 10:00a.m. Mountain Time on Tuesday, February 11, 2014. The call may be accessed by dialing 1-888-317-6016. To participate via the Internet, log on to www.FIBK.com. A replay will be available approximately one hour after the end of the conference call by dialing 1-877-344-7529. The conference ID is 10041082. The call will also be archived on our website, www.FIBK.com. First Interstate BancSystem Inc. was advised in the transaction by Sandler O’Neill & Partners, L.P. as financial advisor, and Christian Samson Jones, PLLC and Holland & Hart LLP as legal counsel. Mountain West Financial Corp. was advised in the transaction by D.A. Davidson & Co., as financial advisor, and Fredrikson & Byron, P.A. as legal counsel. About First Interstate BancSystem, Inc. First Interstate is a financial services holding company, headquartered in Billings, Montana, with $7.6 billion in assets as of December 31, 2013. It is the parent company of First Interstate Bank, a community bank operating 74 banking offices, along with online and mobile banking services, throughout Montana, Wyoming and South Dakota. As a recognized leader in community banking services with 25 consecutive years of profitability, First Interstate’s culture is driven by strong family and corporate values, as well as a commitment to long-term organic growth, exemplary customer service, exceeding customer expectations through its products and services and supporting, with leadership and resources, the communities it serves.