CLE ELUM, Wash. -

More firefighters are on the way to help battle a growing wildfire that destroyed at least 70 homes and burned across more than 40 square miles on the east slope of the Cascades.

More evacuations are expected to be ordered on Wednesday, and officials say the still out-of-control fire could threaten to jump across Interstate 90.

Gusty winds and high temperatures have hampered efforts to deal with the fire burning on grassland, timber and sagebrush east of Cle Elum, a small central Washington town about 75 miles east of Seattle.

By Tuesday night a containment line was built around the southeast corner of the Taylor Bridge Fire, incident commander Rex Reed said.

In addition to the homes, Reed estimated that several hundred outbuildings have burned.

At least 900 people have been evacuated. No injuries have been reported.

Firefighters were trying to keep the blaze out of heavy timber to the north. If the flames reach that abundant source of dry fuel, "that adds a whole new equation," Reed said.

The fire started Monday at a bridge construction site.

A number of homes that burned were along Bettas Road near Cle Elum. An Associated Press photographer witnessed about eight people using hand tools to cut a fire line in an attempt to protect one home.

The grass fire was suddenly whipped up by the wind and came directly toward the group, causing them to scatter. Everyone made it away safely, and the fire slowed, allowing a man with a water truck to dampen the perimeter of the house just in time to save it from the blaze.

Fire commanders estimated the fire has burned across at least 30,000 acres, or about 46 square miles. Fire crews were arriving from across the state. By Tuesday evening, more than 400 firefighters and support workers were on hand.

Joe Seemiller, a captain in Kittitas County Fire and Rescue, and his crews monitored the edge of the fire Tuesday near the Yakima River, trying to keep it from crossing where there is a subdivision of homes nearby on the other side.

"Unless Mother Nature helps us out here, we're going to be fighting this awhile," Seemiller said.

Gov. Chris Gregoire declared a state of emergency for Kittitas and Yakima counties in response to the blaze.

Also, air support from the Washington National Guard has been called in.

The state Transportation Department said a 14-mile section of U.S. Highway 97 was closed because of the fire.

The fire started along Highway 10 between Ellensburg and Cle Elum, said Kent Verbeck, a commissioner and one of the volunteers with Fire District 7. Dry terrain and windy conditions pushed it quickly.

Chane Roghair, 39, worked to dampen hot spots around his 1,300-acre ranch of beef cattle and quarter horses.

Roghair had tanker trucks around his two hay barns to keep them from going up in flames when the fire passed through Monday, and he spent the night keeping watch and dousing spot fires.

No buildings or livestock were lost - his 30 goats hustled down the hill toward the house when the ridge caught fire - but the fire destroyed the original homestead that had been empty for years.

Lands Commissioner Peter Goldmark briefly traveled into the burned area where the fire started. In the distance, black smoke rose from a burning home in a subdivision across the river.

The unusual amount of light fuels created by the cool, damp spring coupled with high temperatures and windy conditions now make for fires so destructive they are impossible to hold or suppress, Goldmark said.

On the east side of the mountains, the winds were supposed to begin to die down Wednesday.

Vacation homes and cabins pepper the scattered forests around Cle Elum.

Brad Rorem and his two sons were at their family cabin preparing to float the Yakima River when they spotted the blaze under the bridge from their deck.