This backfire was set to stem the march of the Mud Lake Complex of wildfires at Big Cypress National Preseve/Jason Longfellow, Florida Forest Service.

A complex of wildfires at Big Cypress National Preserve in Florida has nearly quadrupled in size this week, burning through grasslands, pine and cypress domes. Containment, once at roughly 20 percent, has dropped to about 5 percent as the fires spread.

Preserve officials said Friday morning that the Mud Lake Complex of fires has burned roughly 7,700 acres.

"Fires are expected to grow due to higher temperatures and lower relative humidity, combined with southeast winds," a park release said. "Pockets of heavier interior fuels will continue to burn."

The fires were caused by lightning strikes, according to the park. 

Almost 90 firefighters were battling the flames, with help from six helicopters, three fire engines, and four fixed-wing aircraft. Crews were expected to focus Friday on the Circle and Square fires, which combined Thursday and were moving south in the preserve. Some were also expeted to "continue clearing around camps and private property in the proximity of the Ellison Fire to secure the areas; this may include burning vegetation around property perimeters."

"Additionally, crews will continue to patrol, monitor and mop up hot spots using low impact fire suppression tactics to protect sensitive animals, such as the endangered Florida panther and threatened red-cockaded woodpeckers," a park release said.

The weather forecast Friday called for hot, dry weather, with a 20 percent chance of scattered thunderstorms. Temperatures were to reach into the upper 90s with winds growing to 20 mph.

As the firefighting continues, a temporary flight restriction was in effect in the area, and access to lands managed by Big Cypress National Preserve south of Interstate 75, from mile marker 59 to mile marker 75 (Turner River Road), south to Upper Wagon Wheel Road was temporarily restricted as well. The closure also extends to lands administered by Big Cypress National Preserve north of Interstate 75, from mile marker 59 to mile marker 70, north to the Big Cypress Preserve Boundary. These areas will be closed to provide public and firefighter safety in areas of high fire activity.

These areas are closed to all recreational use including Off- Road Vehicles (ORV), hiking, and camping. This area includes portions of the Florida National Scenic Trail from mile 12, traveling north to the northern boundary of Big Cypress National Preserve.