Copper Culture State Park was established after discovery in 1952 of artifacts relating to the Old Copper Culture. These artifacts date from about 4000 to 3000 BC. Burial ground of North America’s earliest metal users, the Oconto Site is the oldest dated cemetery in eastern North America. The museum is open to the public Thursday-Sunday 11-4, through Labor Day. A foot trail leads from the parking area to a stone monument at location of burial ground. Mill Street, ½ mile west of US 41. National Registry of Historic Places, 1966.