First Texoma National Bank, Post Oak Crossing Branch Basic Info Reviews Routing Numbers Map & Direction Name: First Texoma National Bank, Post Oak Crossing Branch Main Office: No Service: Full Service Brick and Mortar Office Location: 3401 Highway 1417 Sherman, Texas 75092 Grayson County View other branches Phone: 903-813-4898 Please enable JavaScript to view the comments powered by Disqus. Routing NumberProcess ACH TransferProcess Wire Transfer103100878YY111924347YN From: To: