PRIEST RIVER — An aggressive assault has brought the Pioneer Fire to 80% containment with full containment expected by the end of the week.

The fire, which is 2 miles north of Priest River, was first reported July 29. A total of 355 acres have been burned in the fire.

"Night operations confirmed that there is no growth on the fire and the perimeter is secure," Caroline McGough, North Idaho Type 3 IMT public information officer, said.

Crews were scheduled to perform mop-up duties and search for any new fire spots. Mop up standards ensure that the first 100 feet of the fire interior is cold, wet, and inactive, she said.

That aggressive attack, which included a large number of personnel, engines and heavy equipment along with aerial support, enabled crews to get a handle on the fire over the weekend, going from 0% containment on Saturday morning to over 70% on Monday morning.

Continued hot and dry weather expected in the area could allow for continued growth of the fire. Also, afternoon winds could increase fire behavior and the potential for spotting, fire officials said.

A slight weather pattern which moved through the area Monday sprinkled a non-wetting rain on the fire. Overall, weather is expected to remain dry with local afternoon breezes. While cooler temperatures are expected through the weekend, thunderstorms are possible on Friday.

There are 250 personnel assigned to the Pioneer Fire, including 20 engines, seven water tenders, three Type 2A hand crews, 2two dozers, 2 heavy equipment bosses, and a grader. However, McGough said officials are "right sizing our resources with recent demobilizations."

The wildland fire was reported in the early afternoon last Thursday, quickly growing to to 200 acres by early evening and forcing evacuations of several dozen homes in near proximity to the fire. The cause of the fire, which is under the Pend Oreille Forest Protective District, is under investigation.

Evacuation orders are given a "ready," "set" and "go" designation to give residents a clear breakdown of the threat level and the steps they should take under each.

"Ready" indicates people should be aware of the threat and to create a plan. "Set" indicates they should be aware the threat is growing and to begin implementation of their plan. Under "go," the threat is considered imminent and residents should evacuate.

While all residents have been allowed to return home, many areas remain at either "ready" or "set" status.

Under "ready" status include homes on Pup Paw Trail, Beaver Pond Trail, Sno-tika Road, and Bear Paw Road (up to and including Snow Valley Road.) Under "set" status are homes on Barrett Road, Whiski and West Whiski roads, Moose Crossing, Stone Johnny Road, Cuban Creek Road, USFS 984, Bodie Canyon, Kacy Bear Lane, Mundy Lane, Skunk Cabbage Road, Slippery Slope Trail and Saddler Creek Road.

High smoke concentrations are expected to remain over northern Idaho, with impacts from the Canadian border increasing south into the Central Idaho Mountains. Smoke from the wildfire pushed the area's air quality rating for Tuesday to unhealthy levels.

Exposure to air pollutants in wildfire smoke can irritate the lungs, cause inflammation, alter immune function, and increase susceptibility to respiratory infections.

Crews helping on the fire include Idaho Department of Lands, U.S. Forest Service, Bonner County Emergency Management, Bonner County Sheriff’s Office, Stimson Lumber, Idaho Forest Group, and West Pend Oreille Volunteer Fire Department.