A head-on crash early Thursday has left a 31-year-old Minnesota man dead.  The Juneau County Sheriff’s Office reports the vehicle he was driving crossed the centerline on a bridge over the Wisconsin River.  No names have been released.  Investigators say his car hit a pickup driven by a 46-year-old Mauston man.  No injuries were reported for the second driver.  Highway 82 was blocked for several hours and traffic had to be re-routed.