HARPSWELL — Maine firefighters and forest rangers managed to save 10 cottages from a fire that burned about 4 acres on Sheep Island in Casco Bay.

They faced challenges in getting equipment to the island and working in dense underbrush.

No one was injured in the fire, which started about 2 p.m. Friday.

Two people were on the 9.4-acre island while the fire spread quickly due to dry conditions and a large number of dead fir trees. The cause of the blaze is under investigation.

Dan Skillin, a Maine Forest Service firefighter, said extinguishing a fire on an island presents challenges. He said the dozen firefighters from the forest service and surrounding communities had to drag all of their equipment from vehicles to boats.

“Then there is the rockiness and trying to get your pumps in the water,” Skillin said Saturday.

He said it is difficult to fight a fire amid dense underbrush and the possibility of blazing branches blowing down on firefighters.

“Just trying to walk among all that stuff is pretty complicated,” Skillin said.

At one point, Skillin was called off the island after smoke was reported in Pittston and Whitefield, about an hour away. It turned out the smoke was from the Sheep Island fire.

Two Maine Forest Service helicopters poured 40 loads of water, or nearly 10,000 gallons, on the flames. Skillin said firefighters remained on the scene overnight and into late Saturday morning, putting out hot spots.

The island is visible from the shore in Harpswell, Skillin said.

Dry conditions triggered fires in other parts of the state on Saturday.

Firefighters from the Maine Forest Service were flown in to fight a fire late Saturday morning near the top of Mount Abram near Kingfield, and by midafternoon 10 acres had burned.

A Franklin County dispatcher said the fire flared up from an earlier lightning strike. The dispatcher said the fire was in a remote region away from buildings and development.

Early Saturday evening the Maine Forest Rangers and firefighters were battling a wildfire in Cathance Township in Washington County that covered 15 to 20 acres and destroyed two buildings, the rangers said on Twitter.