A Kingsport Man Convicted Of Distributing A Drug Known As Gravel In Sullivan County Has Been Sentenced In U.S. District Court In Greeneville. 43 Year Old Michael Mangum Was Ordered To Serve 10 Years In Federal Prison. Mangum Was One Of 10 People Indicted In August 2014 On A 35-Count Indictment That Led To Numerous Drug, Conspiracy And Weapon Charges. His Sentence Will Run Consecutively To A Number Of Sentences In Sullivan, Greene And Washington Counties.