SIOUX FALLS, S.D. (KELO) -- The motorcyclist killed in a crash Sunday afternoon six miles south of Spearfish has been identified. Sioux Falls man sentenced to 6 years for child porn The Department of Public Safety says 46-year-old Jess Harold Dean Pinkerton, of Belle Fourche, was traveling northbound on US Highway 14A near mile marker 17 when he left the roadway and went over the embankment into the creek. Pinkerton became separated from his motorcycle and sustained fatal injuries from the crash. The cause of the crash is under investigation. The South Dakota Highway Patrol is investigating the crash.