LIMA TOWNSHIP, Mich. (AP) — A Michigan farmer has made a mammoth find while digging in a field.

The Ann Arbor News reports the bones of a woolly mammoth were found by James Bristle in Washtenaw County’s Lima Township. Bristle says he and a friend were digging Monday when they found what they thought was a mud-covered, bent fence post.

University of Michigan professor Dan Fisher confirmed the remains were a woolly mammoth. He and others dug out the skull and a huge tusk.

Fisher says there are only 10 similar sites in Michigan where a significant portion of a woolly mammoth skeleton was found. He says this one was likely 40 years old when it probably was killed by humans.