The state Forestry Department called about 4,000 firefighters Wednesday to the northeast _ from Sonoma and Lake counties north to Humboldt, Trinity and Shasta counties. Fire officials were stretched so thin that 37 fires could not be monitored, department spokeswoman Karen Terrill said.
She said 22 blazes ``have potential to expand and become very serious wildfires.''
In Lake County, the largest of two fires quickly grew to 3,000 acres in just a few hours, threatening about 200 structures outside Middletown, about 70 miles north of San Francisco, Terrill said.
No property damage or injuries were reported late Wednesday, though fires knocked out power to about 20,000 Pacific Gas and Electric customers in Sonoma, Lake and Mendocino counties, company spokesman Lloyd Cokers said.
Fire officials worried what Thursday might bring.
Much of the trouble began at about 4:30 a.m. Wednesday as fire crews scrambled to reach an estimated 125 fires caused by a dry lightning storm.
In Mendocino County, firefighters hustled to put out 60 fires by midafternoon _ but were contending with another 60 as the day progressed.
Aircraft helped lead crews to the hot spots, but many firefighters had to hike a mile or more to reach the flames.
Elsewhere in the West, smoke from Montana's wildfires was creating a health hazard around Glacier National Park, where three large fires were burning on 130,000 acres.
``It's nasty, nasty, nasty out there,'' said Glen Gray, environmental health director for Flathead County. ``If you stay inside and take little breaths, you'll be OK.''
Smoke blanketed the region, with ash covering cars as far as 30 miles away.
``It stinks bad,'' Gray said, ``and it's not going to go away anytime soon.''
However, fire managers reported progress on many of the 16 other major fires burning in Montana. A 3,010-acre fire near Yellowstone National Park could be contained by mid-September, and significant gains were reported on a 38,000-acre complex of fires that is the state's last still requiring evacuations.
In Oregon, a 470-acre wildfire that burned up to the outskirts of the small tourist town of Cascade Locks east of Portland subsided Wednesday. About 200 homes in the area had been evacuated Tuesday, and a former bed-and-breakfast and an abandoned house and barn were burned.