Firefighters initially had trouble getting to the fire due to the road conditions. Once they arrived, the structure fire was well underway and ammunition inside the residence was going off.
A lieutenant with the Carmel Fire Department said he believes the fire began in the chimney.
"The heat, where it gets warm during the day, it's cold at nights, we've been doing that for about a week now," Lt. Aaron Brown of the Carmel Fire Department said.
"That really plays hectic on chimneys," he said. "We're getting into the chimney fire season again with the weather we've been having."
Firefighters said a man had been living in the camp year-round and that the owner was not insured.
Route 69 had to be closed to through traffic while firefighters battled the blaze.