TUCSON, ARIZ. ? Authorities offered a $5,000 reward for information leading to people believed to have been near the starting point of a fire that ultimately destroyed 340 structures on Mount Lemmon.

Authorities say they have no suspects or strong leads in their investigation of the human-caused fire, which began June 17 near a trail southwest of Summerhaven, the town north of Tucson devastated by the blaze. It’s not known whether the 84,500-acre fire was an accident or started deliberately.

After conducting interviews with about 80 people, investigators are looking for four to 10 others believed to have been on the trail at the fire’s start. They hope those people will lead them to the person responsible, said Suzanne Romero, a U.S. Forest Service fire investigator.

Authorities lack descriptions of the people who may have been near the trail and haven’t narrowed down when the fire began.

Fire information officer Dick Fleishman said the fire remained 75 percent contained Friday, but added that firefighters “did get line around the last active piece of fire that could have kept this fire going to the west.” He said it probably would be a few days before the fire was declared fully contained.

The fire is the largest of several burning in Arizona and throughout the West. This year’s wildfire season has so far claimed just more than a million acres.

In New Mexico, Gov. Bill Richardson surveyed the damage Friday from a 5,222-acre blaze burning east of Taos Pueblo, which was 20 percent contained Friday. Richardson announced that the state is releasing $5 million for local fire agencies around the state to buy equipment.

“The toughest weeks are just ahead of us and the prolonged drought cycle gripping the state means several tough seasons ahead of us,” Richardson said.

A small plane drops fire retardant on a wildfire in the mountains east of Farmington, Utah.

Flames from a wildfire in the mountains east of Farmington, Utah, can be seen from nearby homes. The fire began Thursday afternoon.

Jessica Biesinger swings on a tree at Monte Vista Elementary School, in Farmington, Utah, as a wildfire rages behind. Firefighters continued to battle the blaze Friday in the mountains east of Farmington.