TULSA, Oklahoma - A cold case is hot again, as police dig for answers in the disappearance of a Green Country woman.

Shirley Snow hasn't been seen in nearly 40 years. Now, investigators have zeroed in on a field in Arkansas.

Snow went by "Joann." She left for the weekend back in 1975, and her family never saw her again. New clues are pointing to an ex-boyfriend's property.

Tulsa County investigators say an informant told them Shirley Joann Snow was dumped in a well in Etna, Arkansas.

The FBI and Franklin County deputies are helping with the search.

The news brings back an eerie conversation Snow once had with her younger sister, Pauline Norman.

"She told me one time, she said, 'Pauline, if I ever come up dead, you know Ace has killed me and buried me someplace," Norman said Tuesday.

Norman said Snow had gone to Arkansas for a weekend getaway with her boyfriend, Alex Banning, Sr., who went by "Ace."

Norman said the couple had a rocky relationship, but were on good terms that weekend. Snow had three teenage boys, and Norman said her sister would have never left them behind. So, when she didn't come home, Norman feared the worst.

"We almost knew she was dead, because we was a real close family and we never thought she would run off and not come back," Norman said. "We always knew Ace killed her. I always knew."

Banning was named a suspect, but was never charged. He spent six years in prison in the '80s for rape and sodomy, then died in 1993.

Investigators say the land they're digging up is owned by Banning's family.

Norman said she doesn't know why it wasn't searched sooner, but at this point she said the only thing that matters is that her sister is found, so her family can find the closure they need.

"I'd like to have a little memorial, not nothing big, but something to show how much we loved her, you know?" Norman said.

Investigators say there's a well on an adjoining piece of property, owned by Banning's brother.

They say they plan on searching that area Wednesday.