I saw this beautiful little wasp (a Braconid, I think) hunting very actively over standing dead wood. (Or at least it was small trees that looked injured--not sure all was dead.) Size estimated--I would say the body was maybe 8 mm, not including wings and ovipositor--with those it might have been 10-12 mm.
I know this is a very difficult group, but it does look like some photos here identified as Braconidae:Dorcytes:



But also compare Atanycolus (female)


I could never get a good dorsal photo, but did get a couple of dosrolateral shots that show some of the wing venation.
Location: 36.140269, -78.844234

See comments--appears to be a Atanycolus.