They are the Jeffers Petroglyphs, and they were carved on a rocky outcrop of what geologists call Sioux Quartzite, one of the oldest bedrock formations in Minnesota, dating back to the Proterozoic ...

The Jeffers Petroglyphs are a collection of ancient rock carvings that date back over 7,000 years. Located in Comfrey, Minnesota, the petroglyphs are believed to have been created by Native ...

Maverick Adventures is coordinating the event. The first event is on Friday April 12th at Jeffers Petroglyphs in Comfrey, Minnesota. Other events will include volunteer opportunities, field trips ...