ANB Bank is a bank like no other with the strength, talent, commitment, and security to fulfill our business and personal customers' financial needs. First National Bank of Elk City was opened by the Thurmond Brothers on March 21, 1901, with $25,000 in capital. in Omaha, NE 68102. Fort Sill National Bank has locations spread across the US. FSNB offers personal, savings, business, loans and commercial products.