NORMAN, Okla. (AP) – The Oklahoma State Bureau of Investigation is asking for the public's help in identifying a woman whose remains were discovered in a shallow grave six years ago near Lake Thunderbird.

Investigators say the medical examiner's office believes the remains are those of a white female possibly with Native American heritage who was between 30 and 45 years old. She also had given birth to at least one child and had a distinct tattoo of a sunburst on a large portion of her back.

Due to the rate of decomposition, investigators believe she had been in the grave between three months to a year.

Attempts to identify the woman through DNA have produced no results.

The agency is asking anyone who might have information about the missing woman to call 1-800-522-8017.