Flames lit up the early morning sky and the smoke could be seen for miles as 150 wooden pallets and scrap lumber went up in flames.

Rick Garrett lives across the street from where the fire broke out. He was sleeping at the time, "Basically it was light outside when it shouldn't be," said Rick Garrett, a nearby neighbor.

Firefighters from Kuna and Meridian battled the blaze into the morning.

"It was very, very close to a structure there. We just basically let the pile burn and we protected the structure," said Greg Mcpherson, a Kuna firefighter.

Firefighters says the scrap lumber in the open field fueled the blaze and fire crews had to tap into an irrigation canal to pump water to help put out the flames.

The fire is out, but authorities say the investigation on the cause is far from over, "We're believing it was human caused at this point," said Garrett.

Idaho's Department of Environmental Quality said the fire has affected local air quality.

The entire Treasure Valley is under a yellow air-quality alert and outdoor burning is banned.

The DEQ said smoke drifting in from California wildfires is also still a problem, but the DEQ is predicting big improvements to air quality by Wednesday.