ALCONA COUNTY, Mich. (AP) — Law enforcement is working to identify the remains of a woman who was found in northern Michigan more than 20 years ago.

Michigan State Police have released forensic artists’ renderings of the woman. State police say her remains had been in the woods in Alcona County for four years before a hunter discovered them in 1994. The Alcona County Sheriff’s Department and the state police crime lab worked together to recover the remains.

Authorities say evidence of a skull fracture indicates the unidentified woman may have experienced trauma at or near her time of death.

Michigan State University anthropologists say the woman was likely 30 to 50 years old, and approximately 4 feet 7 inches to 5 feet 6 inches tall.

Advancements in DNA technology have aided authorities in the cold case investigation.