While I was down in Clarksville this past weekend, Geoff Walden, an expert on the KY Orphan Brigade, who lives there, took me by the Camp Boone site. The sign is indeed back up!
There is also a large error on it - the KY units that camped there were infantry - not cavalry as the sign states!
Further north up the road a couple miles is the site of Camp Burnett, a split off camp for the KY Orphan Brigade. The little hamlet on the railroad tracks (something Station) is where they boarded the trains for Bowling Green. Maybe we should do signs for those too.