KALISPELL, Mont. -

Crews continue to battle the state’s largest wildfire northwest of Missoula. It is located off Highway 200, near Thompson Falls.

Officials say two fires have merged in the Thompson River Complex.

NBC Montana was on the scene and saw firsthand what fire officials are doing to combat the flames.

A lightning strike caused the fire, and it has been burning for several days. Over 600 acres have been burned.

The rugged terrain and steep slope of the mountain limits access for firefighters on the ground.

“That isn't a very good combination for a firefighter or for anybody really. It’s just a pretty dangerous situation to walk on, let alone fight fire on," said John Hamilton, of the U.S Forest Service.

That’s why fire officials have started making water drops. It started with only one helicopter making the drops. But, when the winds started to pick up, two more helicopters joined the fight.

Several people driving by stopped on the side of the road to get a good look. Most of them say that seeing wildfires is something you expect in the summertime, especially with weather conditions. With temperatures in the upper 90s, and winds reaching up to 25 even 35 miles per hour, weather is a concern for firefighters.

“It’s a bugger to get around in and no place to find a good safety zone; we don’t want to put any firefighters in danger,” Hamilton said.

Residents who live in the area tell NBC Montana the hazy skies and the air quality are something they can’t get away from.

"You can smell the smoke. I’ve had a sore throat for the last few days because it’s kind of stuck in this valley. I hang my clothes on the line and when you bring them in it smells like smoke, like a campfire,” said Thompson Falls resident Krista Olesen.

But residents including Olesen aren’t worried too much.

"I worry that if the wind comes by that it could come over, but it seems like there’s enough space between us. We live just a little bit down the road and it seems like they’re [the firefighters] pretty aggressive with it," Olesen said.

"We have pretty professional people here that know what they’re doing with fire,” Hamilton said.

So far, no buildings, people or property have been threatened. There have been no evacuations. Firefighters will continue to work day and night to contain the fire.