Arthur, N.D. (Sept. 17, 2018) – First State Bank of Warner (S.D.) has been acquired by Arthur, N.D.-based BankNorth. Its branch locations in Warner and Aberdeen, S.D. opened today under the new name. BankNorth’s holding company, First Financial Corp., announced the acquisition in March 2017 and recently fulfilled all regulatory requirements to finalize the merger of the two banks. “We’re delighted to welcome First State Bank of Warner customers and employees to the BankNorth family,” said BankNorth President James L.…