Ken --
I'm overwhelmed with new messages since our computers have been down for nearly two weeks due to the ice storm. However, NPS staff from the Santa Fe office visited the state in the early 1990s to locate this site. It's included in the final report of the Civil War Sites Survey Commission which was staffed by the American Battlefield Preservation Program (also of the National Park Service).
There's a listing for Middle Boggy (Muddy Boggy) at the ABPP site at nps.gov
(How's the booklet coming?)