A Watauga man was injured in an afternoon single-vehicle wreck on US 321 near Riverview Grocery.  The 4:40pm crash occurred as Joseph Randall Keller lost control of his 2002 Ford Taurus, the car hitting the ditch line and running along the ditch for some distance before striking a large rock, according to trooper Alexander.  Keller, 53, of Peoria Road, was transported to Watauga Medical Center suffering a gash to his head, Alexander saying that he appears to have had a blackout due to a diabetic issue and he filed no charges.