Dennis,
I'm not familiar with that one in particular, but there was a lot of minor activity over in that area. It wouldn't have come from St. Marks, though, because the Confederates held that position until the end of the war.
There was a pretty sharp little skirmish on the Aucilla River involving a Union boat party and a number of deserter/Unionist raids into the area. There was also, of course, Camfield's expedition into Taylor County to try to round up W.W. Strickland and his "United States of Taylor" men.
Dale