“When you come here, you’re stepping back 150 years into the past. You can’t do that very many places,” A lot of Hart: Volunteers put pieces of history together Joe Merten likes to say the Hart Historic District is “the best-kept secret in Oceana County... that isn’t a secret anymore.” For 26 years, Merten and a dedicated corps of volunteers from the Hart Heritage Preservation Group have worked diligently to save some of the area’s historic buildings — and people’s belongings