This year is Red Hook’s bicentennial. When local officials conduct a commemorative opening ceremony at 1 p.m. on Saturday, May 12, rather than the usual conventional notion of progress, many residents will cherish how much the town hasn’t changed: how it’s still mostly surrounded with productive farmland. “We have 3,000 acres under cultivation. That makes Red Hook the premier township in the Hudson Valley for agriculture,” said Christopher Klose, a member of the bicentennial committee and vice president of the local Historical Society.