InciWeb photoFirefighters gather on U.S. 94 in Charlton County with the West Mims Fire visible nearby.

FARGO — The entire southern half of Charlton County has been ordered to evacuate in the face of the spreading Okefenokee Swamp fire, officials said Tuesday.

The evacuation order affects between 1,500 and 2,000 people, said County Administrator Shawn Boatright.

The fire, first reported April 6, has grown to more than 140,000 acres and has jumped U.S. 94 in its southward push, according to a statement from the Okefenokee National Wildlife Refuge. Residents of the communities of St. George and Moniac were advised to evacuate during the weekend; evacuation was later made mandatory.

Anyone in the evacuation zone should take the situation seriously and leave, said John Nicholls, a public information officer with the West Mims command post.

A 300-bed shelter has been opened in the town of Kingsland, but as of Tuesday afternoon, no evacuees had shown up, said Glenda Barber, American Red Cross shelter manager.

“We had a few people call, but when we told them ‘no pets,’ they decided not to come,” she said.

Almost 700 firefighters are battling the blaze, and the aerial fleet is now supplemented with a huge jet airliner converted for firefighting use.

A DC-10 air tanker, flying out of Chattanooga, Tenn., will be making two-hour turnaround runs, dropping 12,000 gallons of fire retardant each time.

“It can pack a powerful punch,” Nicholls said.

The DC-10’s tankage is compartmentalized so some of the retardant can be dropped on different spots during the same flight, he said.

The ability to get water and equipment to the right spots is complicated by the fact that firefighters are battling a blaze in a swamp, Nicholls said.

The worst of the blaze is concentrated in the southern and eastern areas of the Okefenokee. The town of Fargo, on the western edge of the fire zone, was a center of concern early on, with residents told to stand by for possible evacuation, but Nicholls said the fire “isn’t aggressive” in that area right now.

A particular concern of firefighters now, Nicholls said, is “needlecast,” in which pine needles dried out by the fire fall from dead or damaged trees after firefighters have already cleared an area — producing more dry fuel for the flames to re-ignite later.

The Stephen C. Foster State Park, located inside the refuge, is closed, and many activities in the national refuge itself have been canceled or curtailed. The main entrance to the refuge is closed. U.S. 94, which runs from Valdosta to St. George, is closed in Charlton County.

Terry Richards is senior reporter at The Valdosta Daily Times.