Wildfires near the Georgia-North Carolina line are spewing smoke so thick that residents are being urged to wear special masks if they must do outdoor activities.

The fires have prompted evacuations in Georgia, North Carolina and Tennessee in recent days.

The largest of dozens of ongoing wildfires in the South has now burned 13,300 acres — or more than a third of the vast Cohutta Wilderness area — in the north Georgia mountains just south of the Tennessee line, fire managers said in an update Saturday. It was only 20 percent contained.

In Macon County, North Carolina, special health masks were being made available Saturday. Emergency Management Director Warren Cabe said they're distributing N95-rated masks as regular surgical masks don't provide adequate protection from smoke particles.