COMMUNITY 1ST BANK SHAREHOLDER ALERT: Rigrodsky & Long, P.A. Announces Investigation of Merger

Rigrodsky & Long, P.A. announces that it is investigating potential legal claims against the board of directors of Community 1st Bank (“CMYF” or the “Company”) (OTC PINK: CMYF) regarding possible breaches of fiduciary duties and other violations of law related to the Company’s entry into an agreement to merge with First Interstate BancSystem, Inc. (“First Interstate”) (NASDAQ GS: FIBK) in a transaction valued at approximately $21.5 million. Under the terms of the agreement, shareholders of CMYF will receive 0.3784 shares of First Interstate common stock for each share of CMYF common stock.