A man is dead after his pickup truck rolled down an embankment along State Route 6 at the turnoff to Thistle in Spanish Fork Canyon on Tuesday afternoon.  According to the Highway Patrol, the single occupant crash occurred sometime before 1:20 p.m.  There were no witnesses to the crash, and the man was found deceased at the scene.  Investigation into the cause of the crash is continuing, but the area is known for accidents cause by high rates of speed.