Here ya go!! www.snickersvillehounds.com for a July 4 9am $20 in Middleburg off Sam Fred Rd at Sunnybank Farm. I think it's a potluck picnic after. I think they do 2 groups. One walk/trot. Not going but will someday.
Most of the hunts aren't having July rides but almost all start up August 1 so watch the Fauquier Times horse sport section for times/places etc.
I "think" Casanova is having summer evening rides on weeknights too but I don't know the schedule. They do a terrific summer foxhunting camp perfect for green horses. As does Rappahannock Hunt I believe. Dates unknown.
email@example.com is a well maintained list of all Va. trailrides. You can get on their emailing list.