LEWISTON, Idaho -

Five structures have burned and firefighters are battling rugged terrain to stop the Big Cougar fire, which has burned 41,000 acres south of Lewiston along the eastern shores of the Snake River.

On Thursday helicopters lifted bucket after bucket of water from the Snake River and raised them hundred of feet up the canyon walls to the Big Cougar fire.

“This morning it was about 41,000 acres and we anticipate that to grow a little more today,” Incident commander Mike Almas said. “Things are going well we expect a lot of progress today."

The lightning sparked blaze has ripped across steep grassy land posing problems for firefighters.

“It's steep, grassy, fast moving fire are some of the challenges, communication is a challenge because we do come up the canyon bottom up to high elevation and, you know, rattlesnakes,” Almas said.

Crews on the northern side of the fire lit a back burn Thursday in hopes of slowing the fire's progress.

"The fire is going really well, like I said earlier it's just, we're just setting up for a couple of big operations that hopefully if they go well we'll catch this thing," Almas said.

Fire managers are asking boaters on the Snake River to be aware of the fire and the helicopters pulling water from the river.

Level 2 evacuations were put in place for the communities of Waha and Redbird as a precaution while Level 3 evacuations remain in place for homes between China Garden Creek and Captain John Creek.