ALLAGASH – Law enforcement agencies are investigating two fires that destroyed several buildings early Sunday at two North Maine Woods checkpoints.

Volunteer fire departments from Allagash and St. Francis fought the fires, which occurred about three miles apart on the Little Black River and the St. John River.

An official of North Maine Woods, owner of the three destroyed structures, said damage was between $30,000 and $40,000.

“There was definitely a human element involved in the two fires,” Investigator Tim Lowell of the State Fire Marshal’s Office said Tuesday. “We have been conducting interviews since Sunday.”

Burned to the ground were two buildings and a house trailer.

The building at the Little Black River Checkpoint, a 16-by-30-foot wood-framed construction building, was 2 years old. The 14- by 14-foot wood-framed building at the Dickey Checkpoint was older. Also destroyed was an older model house trailer.

Lowell said the Little Black River Checkpoint fire was reported by a passer-by at 5:10 a.m. Sunday. When Allagash volunteer firefighters were at the scene, they saw smoke over the horizon from the fire at the Dickey Checkpoint and called the St. Francis firefighters for mutual aid.

“Both fires were burning at the same time,” Lowell said. “Firefighters could see the smoke from the other fire as they fought one fire.”

“The investigation is well under way,” he said.

Lowell would not discuss how the fires were set. Involved in the investigation with Lowell are members of the Maine State Police, forest rangers and game wardens. Investigators were looking into reports of a party going on during the night Saturday at Walker Brook, just a few miles from both checkpoints.

“We have a zero tolerance policy for arson,” Albro Cowperthwaite, executive director of North Maine Woods, said Tuesday afternoon. “We are offering a $1,000 reward for information leading to the arrest and conviction of people involved.”

Cowperthwaite said the two buildings will be rebuilt as quickly as possible. Normally, the checkpoints are staffed from mid-May until November. North Maine Woods manages nearly 3.5 million acres of forestland owned by more than 20 landowners. The checkpoints allow officials to know who is coming and going in the forest and who is in the forest at any given time.