Kidnapping of Federal agent during Prohibition

[Colleen Matoon]

I am looking for the title of a book that took place somewhere like Arkansas or Oklahoma. The dialogue was written in the dialect of the area. A Federal agent is investigating illegal moonshine operations during the Prohibition, and the family kidnaps him. The wife ends up having an affair with the agent. I think the word "Moon" is in the title.

[Lobstergirl, au gratin]

Fiction or nonfiction?
Cover?
Author's gender?
When did you read it or when was it published?