NORTH COAST, Calif. – A pair of lightning-caused wildland fires in northern Mendocino County scorched more acreage on Friday as firefighters also made a gain in containment.

The North Pass Fires, burning since early last Saturday morning, had burned 21,558 acres by Friday night, with containment increasing to 18 percent, according to Cal Fire and the US Forest Service’s unified command on the incident.

The fires, burning 10 miles northeast of Covelo in the Williams Valley, continued to threaten dozens of residences east of Covelo, where officials said evacuations remained in effect on Friday.

Approximately 1,191 fire personnel were assigned to the fire on Friday. Other resources included 110 engines, 26 fire crews, two airtankers, seven helicopters, 32 bulldozers and 23 water tenders, unified command reported.

Officials said the fires were actively burning in heavy timber into the Yolla Bolly Middle Eel Wilderness and continuing to spread to the East to Forest Road M1, south towards Anthony’s Ridge, north to Cedar Springs Ridge and northeast towards Pothole Creek and Steel Bench.

Firefighters continued to establish and improve containment lines while defending structures. They also made good progress on the west and southwest perimeter of the fire along Asa Bean Road, and the fires moved to within half a mile of Anthony Ridge along the Buck Creek drainage, according to the Friday evening report.

Incident command reported that smoke was likely to be especially heavy in the Covelo/Round Valley areas, where smoke concentrations have reached levels considered to be “hazardous” under state and federal air quality standards.

Those air quality conditions are expected to remain unchanged Saturday and for a few days afterward, fire officials reported.

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