Tracing Hatfields in WV is like finding a needle in a haystack sometimes. I'm a descendent of Captain Andrew Hatfield.Most of his descendents lived in what is now Cabell Co., WV. He had a brother Joseph who's son is the Ephriam Hatfield that settled in the Tug River Valley. His descendents include Devil Anse.
I can offer some suggestions on how to find out more.
WV Heritage Encyclopedia
The Hatfields, Hatfield,G. Eliot Big Sandy Valley Historical Society
Hatfield Family History, Genealogy Trees
"The Name and Family of Hatfield"
Virginia Magazine of History
The Big Sandy by Ely .. (1887)
Johnston's History of the Middle New River Settlement's (1905)
Family Bibles Historical Records
US pension records
Your Ancestors and Mine, WV Family Bible Records
Courthouse Records of Births and Marriges

Keep in mind that prior to the Civil War,all the records would be for places in VA and counties split or combined to present day counties.
Also many counties published their own histories. Contact public libraries and historical societies in the area.
Good Luck