Darrell Bohannon, Carrol County ranger for the Arkansas Forestry Commission, said the blaze was more than likely caused by someone burning trash.
Bohannon said he intended to serve a citation in the case this week.
If found guilty, the perpetrator could face as much as $1,000 in fines, as long as one year in prison, or both. Civil penalties are also possible, should those impacted by the fire choose to file suit, Bohannon said.
Bohannon said he and Stone County Investigator Russell Lancaster, who has also been working the case, had flown over the burned area last week.
"We could spot the origin from the air," he said.
Last month's fire burned for two days before firefighters were able to contain it.
Firefighters from Green Forest, Oak Grove, Marble, South Carroll County, and Alpena, and Forestry Service rangers from three counties labored day and night to contain the blaze.
Twenty volunteer Caddo Native Americans from Oklahoma were also called in to relieve local firefighters.
Though evacuation proved unnecessary, dozens of residents were told to prepare for that possibility. In the end, no structures were damaged, and no injuries were reported.