UPDATE: Fire investigators said more than half of the 67 fires burning right now have been deliberately set.
And so far, seven suspects have been arrested for arson state-wide, but more arrests could be made in the near future.
The Sequatchie County Sheriff's office arrested a man for setting a small wildfire by throwing a lit cigarette into a pile of leaves and watched it burn.
Deputy Chief Randall Lockhart said more than 900 acres have burned in Sequatchie County because of two arsonists.
On Standifer Grant Road, Matthew Wallace admitted to tossing his lit cigarette in the brush.
"He didn't try to put it out or did not call anybody to try and put it out," Deputy Lockhart said.
Days earlier, Andrew Lewis, 21, was charged with arson in two different wildfires. He's now facing serious jail time.
"I know they're going to prosecute the first guy with about 900 acres up here, they're going to prosecute him with a felony," Lockhart said.
Firefighters and law enforcement across the state said they've had enough. They're exhausted from fighting the fires, most of which were intentionally set.
18 of 31 fires burning in the Tennessee Valley are suspected arson, including one of the most dangerous fires on Mowbray Mountain.
"If one of our first responders is injured badly or is god forbid killed fighting these wildfires, I can promise you the full weight of state government will come down upon you," said David Purkey, TN Commissioner of Safety and Homeland Security.
Deputy Chief Lockhart said the wildfires in Sequatchie would still be burning and threatening homes if it wasn't for assisting agencies and local volunteers.
"Most of these fire departments are volunteer, they have a regular job, then they go out and help fight this fire the rest of the night. And that's just something that we can't appreciate how much help and how much work they do," he said.
Law enforcement agencies across the state promise more arson arrests will be made relating to some of these wildfires.
If you see anything suspicious call police immediately.
The Tennessee Department of Agriculture set up an arson tip hotline. The number is 1-800-762-3017.
If anyone calls in a tip leading to an arson arrest they could receive up to a $2,500 reward.
For daily updates on active TN wildfires and their suspected cause, click here.
Andrew Scott Lewis, 21, of Hamilton County, has been arrested for setting three fires on Smith Mountain and Blue Swanee Mountain.
Several people had reported seeing a red Toyota truck in the area when the fires started. The truck was spotted in town last night and after deputies questioned him, Lewis admitted to setting the fires.
Lewis is charged with three counts of setting fire to personal property or land and one count of vandalism of property over $250,000, which is a Class A felony.
Stay with Channel 3 and WRCBtv.com for more on this developing story.