A fatal accident closed Highway 89 in Paulden for about four hours yesterday.  DPS says the accident happened at around 5:47 a.m. when a Hyundai Elantra was heading southbound.  A freight truck was heading northbound.  A witness behind the truck told troopers the Elantra crossed the center line and collided head-on with the truck.  The driver of the Elantra, 29-year-old Ryan Greenleaf of Paulden, was pinned in the vehicle and was pronounced dead on the scene.  The two vehicles collided at the left front corners and continued past one another in a side-swipe manner.  The driver of the freight truck was not injured.  Highway 89 reopened in the area at around 9:56 a.m.