KETCHIKAN (KDN) â Alaska Department of Transportation workers on Thursday morning painted over offensive graffiti that had been left on a swath of South Tongass Highway. The vandalism near mile 4 South Tongass Highway occurred at some point midweek, and followed similar graffiti vandalism that had occured this past weekend at Schoenbar Trail and the Ketchikan Skate Park. The graffiti at the Schoenbar area locations was cleaned up by Sunday evening by City of Ketchikan and Ketchikan Gateway Borough public works crews. A Thursday statement from the Alaska State Troopers Public Information Office said that the department is investigating the South Tongass Highway occurence, and has informed the Ketchikan Police Department as they investigate any ties between the two incidents.