SPOKANE, Wash. -- With a wildfire fueled by strong winds tearing through timber in its path, authorities in Central Washington have urged residents of nearly 900 homes to flee.

There was zero containment Wednesday in the Chiwaukum Creek fire burning about 10 miles north of the Bavarian-themed village of Leavenworth. In that town, the temperature hit 104 and a light dusting of ash fell.

The fire's smoke plume, visible for miles, rose 25,000 feet into the air.

The blaze closed 35 miles of U.S. Highway 2, stretching from Leavenworth to Stevens Pass in the Cascade Mountains.

Residents of 860 homes have been told they should leave immediately, fire spokesman Rick Acosta said late Wednesday. A Chelan County emergency management spokeswoman said earlier that another 800 homes were less seriously threatened.

With more heat and winds gusting to 30 mph forecast for Thursday, Acosta said fire officials were putting the new day's plan together late Wednesday.

Another fire spokesman earlier estimated the Chiwaukum Creek fire's size at nearly 2 square miles but Acosta said it was so smoky and the fire had moved so quickly that officials just didn't know how big it was. It was first detected Tuesday.

Nearly 1,000 firefighters were on the lines at the Chiwaukum Creek fire, the Mills Canyon blaze near Entiat and a third wildfire. The containment level on the Mills Canyon fire, the state's largest at 35 square miles, held steady at 40 per cent.

Worsening wildfire activity has prompted the governor's offices in both Washington and Oregon to declare a state of emergency, a move that enables state officials to call up the National Guard. In Washington, that declaration covers 30 eastern Washington counties.

State fire assistance was ordered for the Carlton Complex of fires burning in north-central Washington's Methow Valley, where residents of about a dozen homes have been told to leave. Spokesman Jacob McCann said Wednesday evening that complex has burned across 7 square miles with zero containment.

The Washington National Guard sent two helicopters and 14 people to help.

Wildfires were also burning in Oregon, Utah, Idaho and California.

In southern Oregon, a Klamath County wildfire turned out to be more destructive than authorities initially believed.

After the fire burned in the rural Moccasin Hill subdivision near Sprague River earlier this week, officials reported that six houses were destroyed, along with 14 outbuildings. But fire managers toured the burn area Tuesday and spokeswoman Ashley Lertora said they found 17 residences and 16 outbuildings destroyed.

A fire that started Wednesday afternoon in a northeast Oregon field west of Heppner raced quickly across as much as 20,000 acres, or some 30 square miles, before firefighters from two counties got it stopped, the Morrow County sheriff's office said.

Undersheriff Steven Myren said no homes or other structures were lost, "although the fire did get uncomfortably close to some."

Oregon fire officials said Wednesday that the Bailey Butte fire -- part of the Waterman Complex -- had burned more than 3 square miles west of Mitchell and was moving south into the Ochoco National Forest in central Oregon. Two other fires near Service Creek and Kimberly brought the Waterman Complex to more than 6 square miles, or 4,000 acres. The fires are in timber, grass and brush.

In north-central Oregon about 15 miles north of the town of Warm Springs, the lightning-caused Shaniko Butte fire spread quickly in dry, grassy fuels. Pushed by wind, it had burned across 20,000 acres by late Wednesday. It started Sunday.

In Utah, a wildfire encroaching on homes in the Tooele County town of Stockton had burned about 400 to 500 acres. Utah Division of Forestry, Fire and State Lands spokesman Jason Curry said the fire burned part of a water tower but it's believed no homes have been destroyed.

In central Idaho, the lightning-caused Preacher Fire has scorched nearly 53 square miles in two days, burning quickly through grass and brush. But fire managers said Wednesday they had made good progress.

Evacuation orders have been called off for several rural homes in Northern California as firefighters took advantage of cool, moist conditions.

Some residents near the fire in Shasta County have been advised they may need to evacuate again, and the blaze that has burned more than 10,000 acres -- or nearly 17 square miles -- still poses a threat to nearly 70 homes, state fire officials said in a statement Wednesday night.

The fire was 40 per cent contained, up from 20 per cent on Tuesday.

Marijuana-growing activity led to the fire breaking out on Friday and subsequently destroying eight homes, authorities said.