From Seattle to Denver: Smoke from Oregon wildfire blows across the U.S.

People in Oregon covered their faces with scarves to keep choking ash from wildfires from filling their lungs and wiped the soot from windshields, similar to what long-time residents said they had to do in 1980 during the volcanic eruption of Mount St. Helens.

The growing blaze east of Portland, Oregon, in the scenic Columbia River Gorge, was one of dozens of wildfires in western U.S. states that sent smoke into cities from Seattle to Denver -- prompting health warnings and cancellations of outdoor activities for children by many school districts.

The 16-square mile (41-square kilometers) fire east of Portland forced hundreds of home evacuations. And embers from the fire drifted across the Columbia River -- sparking blazes in neighboring Washington state. People shielded their faces and authorities in the Northwest urged drivers to use headlights during the day to increase visibility.

"I haven't seen ash fall like this in the Portland metro area in my 18 years as a firefighter," said Damon Simmons, with the fire incident management team for the Oregon State Fire Marshal.

Joanna Fisher walked to work Tuesday at a Troutdale, Oregon, naturopathic clinic with Calla Wanser, who was wearing a red bandana around her mouth.

"You can't really stand outside without getting rained on" by ash, Fisher said.

The only comparison people could come up with was the eruption of Mount St. Helens in nearby southwest Washington more than 35 years ago.

"In 1980, we had a couple of significant ash falls here in the Portland area and this is very reminiscent of what we saw in the ash fall in those days," said Don Hamilton, a spokesman for the Oregon Department of Transportation. "The particulate matter that shows up on the cars, it gets in your hair, it gets in your eyes, its all over the place like it was in those days."

A closure of one section of Interstate 84 because of thick smoke and falling ash was extended 30 miles (48 kilometers) east of Portland while the U.S. Coast Guard closed about 20 miles (32 kilometers) of the Columbia River in the same area.

The National Interagency Fire Center in Boise, Idaho, a federal agency that coordinates wildfire-fighting, said 80 large fires were burning on 2,200 square miles (5,700 square kilometers) in nine Western states.

A fast-moving wildfire in northern Utah swept down a canyon Tuesday morning -- destroying structures, forcing evacuations and closing highways.

A least five homes burned and more than 1,000 people were evacuated as high winds fed the flames in the canyon north of Salt Lake City. Thick black smoke closed parts of two highways as firefighters struggled to fight the blaze fueled by winds gust at up to 40 mph.

In Washington state the U.S. Department of Defense agreed to assign 200 active-duty soldiers to help fight a wildfire.

Civilian firefighting commanders said Tuesday the soldiers from Joint Base Lewis McChord, Washington, would undergo four days of training and then be sent to a complex of 14 wildfires in southern Oregon's Umpqua National Forest that have burned 47 square miles (120 square kilometers).

And a wildfire near Mount Rainier National Park in Washington state grew to more than 29 square miles (75 square kilometers) and heavy smoke blanketed many cities in Washington state. A portion of the park was closed.

Mandatory evacuations were called for the fire near Mount Rainier, including the Crystal Mountain ski resort, which closed Monday because of smoke.

The air quality in Spokane, Washington, was rated as hazardous Tuesday morning. The National Weather Service says it was likely to get worse as wind shifts bring in smoke from fires in Canada, Montana, Oregon and Washington.

Air quality alerts were issued for parts of Idaho as well.

In Oregon, people living in about 700 homes in and around the Columbia River Gorge have been forced to evacuate. Others have been warned to get ready as flames burn trees and brush in one of the state's biggest tourist attractions.

Authorities say they believe the blaze, which started Saturday, was caused by a 15-year-old boy and friends using fireworks. They've identified a suspect but have made no arrests.

Gov. Kate Brown visited the fire scene Tuesday as ash fell around her.

The fire spread 13 miles in 16 hours, pushed by winds overnight that ranged from 30 mph to 40 mph in tinder-dry conditions, Brown said.

"It looks like there has been a devastating impact on the Gorge," she said, speaking of the renowned Columbia River Gorge, famous for its hiking and spectacular vistas.

A total of 600 Oregon National Guard troops have been called up to fight more than a dozen blazes across Oregon, including a much larger blaze in southwest Oregon in a rural area along the California border.