Michigan, tribal partners digitally preserving petroglyphs

CASS CITY, Mich. (AP) — Michigan's state archaeologist says more than 100 ancient rock etchings at Sanilac Petroglyphs State Park are being digitally preserved through a partnership with tribal groups.

MLive.com reports that the Michigan Department of Transportation is using special technologies to scan the Native American petroglyphs and build digital models of them that will help document the site and track its preservation.

The project comes a year after vandals damaged some of the petroglyphs at the 240-acre park that's about 85 miles (135 kilometers) north of Detroit in Cass City.

State archaeologist Dean Anderson says some of the stone etchings could date back as much as 1,400 years.