The Bank N.A. of Oklahoma began in May of 1927, when a group of McAlester businessmen met and agreed to take over the charter of The Bank of McAlester, a small State bank that had closed. The group opened on May 17, 1927 with Tom Hale as President, Roy Caldwell as Executive Vice President & Cashier, W.B. McAlester and W.J. Basolo as Vice Presidents. Board members were W.P. Mullen, Ben T. Childers, W.P. Freeman and L.O. Bradford along with the four mentioned officers.

The Hale Family represented the major shareholders until 1989, when the interest was sold to Fern Oliver Testamentary Trust, with Mike McGowa, the current Chairmen and CEO, as Trustee. Three generations of the Hale Family gave The Bank N.A. its successful legend. Elmer Hale succeeded as President in 1941 and served until his death in 1969. Elmer Hale, Jr. served as Chairman of the Board from 1969 until 1989 and continues as Chairman Emeritus.

In October of 1986, a branch was acquired in Stillwater, when the char ter of the Stillwater Community Bank was declared insolvent by the FDIC. The following year, a branch in Holdenville was acquired the same way, when The Peoples State Bank was closed. In 1988, Citizens State Bank of Maude was closed and The Bank N.A. opened its fourth location. The mission of the McAlester bank was extended to each of these branches. .