Erin Hart, Irish mystery series

I was introduced to a new author Erin Hart, partly because her books are Irish/celtic, partly because the latest one takes place in MN and partly because she has a beautiful way with language. I love this quote: The celts speak in riddles, hinting at things, leaving much to be understood (Poseidonius, Greek Ethanographer of 1st century BC).
These are the Nora Gavin (american pathologist) and Cormac Maguire (Irish archeologist) award winning series that take place primarily in bogs, in Ireland. Haunted Grounds was the first (2003) then Lake of Sorrows (2005) then False Mermaid (2010). The first novel is based on a true story (she first heard of in 1986 when visiting) of finding a severed head of a woman with red hair (probably from the 1650s Cromwell era) in 1955 - she was able to speak to the people involved! She wanted to create a story because so little could be learned of the girl. The haunting descriptions are theirs as well as family experience (her husband is Paddy Orien). "the past is not buried, but lives and breaths" - e.g. peat.
They really need to be read in order, but there's only three (and she is a slow writer, so you are lucky to catch up now!).

Her favourite authors are PD James, Dorothy Sayers, with Elizabeth George and Umbretto Eco in the mix. She would also like to take AS Byatt to lunch at WAFrost. She is currently reading Geraldine Brooks People of the Book as her next novel will involve an ancient manuscript! These remind me a bit of Sharyn McCrumb, whose appalachian series I adore (for Nora Bonesteel), with that local flavour, myth/folklore/historic detail. Some gothic suspense, similar to Mary Stewart (I always wished she had written more novels about the same people). And the chilling forensic details are reminscent of Kathy Reichs and Simon Beckett. Softer story, with rather tumultous love affair, maturing, but with issues.