A wildfire burning northeast of Trout Lake grew to more than 500 acres Sunday and blocked access to a popular climbing route on Mount Adams.

The plume from the Cold Springs fire was visible from Portland to Yakima on Sunday.

The head of the fire was working its way toward the edge of the Yakama Nation reservation on the east side of Mount Adams, a U.S. Forest Service spokesman said.

More firefighters had been ordered, and an incident management team from Central Oregon was scheduled to take command this morning, spokesman Chris Strebig said.

The fire was burning about 11 miles northeast of Trout Lake, south of Mount Adams. Officials suspect lightning from a storm earlier this month ignited the fire, which was reported about 8 p.m. Saturday, Strebig said.

He said the rugged terrain, dry conditions and stands of bug-killed timber were hampering the attack.

The Forest Service had closed roads to the South Climb trailhead, a popular Mount Adams climbing route. Hikers coming off on the mountain were being directed around firefighting equipment as they drove away.

Three tanker planes and two helicopters were dropping retardant or water on the flames. Ground crews and fire engines had also been dispatched, Strebig said.

A Toppenish air-quality monitor was reporting conditions considered unhealthy for sensitive groups, such as people with respiratory problems. The Yakima monitor was reporting good levels.

An air-quality forecast for the week was not available Sunday from the Yakima Regional Clean Air Authority, which operates the monitoring devices.

Two hundred Spokane Valley residents who were forced to evacuate by Friday’s destructive fire that burned 13 homes were allowed to return to their homes on Sunday.

The evacuation order was reduced from Level 3 — which means residents have to leave when ordered — to Level 2 — which means residents have to be ready to leave.

“They’re coming in as they feel like it,” fire spokesman Dale Warriner said. “They’re just going back home.”

Meanwhile, 250 firefighters were mopping up the 1,006-acre Spokane Valley wildfire on Sunday, reporting it 60 percent contained.

On Saturday, officials said a small recreational fire that rekindled in high winds, allowing embers to escape, started the fire.

The person believed to be responsible had been identified, but the identity was being withheld pending completion of the investigation, fire supervisors said. Once the investigation is completed, the state Department of Natural Resources will determine an appropriate course of action, they said.

“We’ll be long gone when the investigation is completed,” Warriner said.

In other major wildfires in Washington on Sunday:

• The Willow Lakes fire was reported about 9:20 a.m. Sunday and by 6 p.m. had covered 20,000 acres, or 31 square miles, southeast of Soap Lake, said Gary Garnant, public information officer for the Grant County Department of Emergency Management.

• The Badger Mountain wildfire eight miles north of East Wenatchee was up to 14,000 acres, with 210 homes threatened. A total of 313 firefighters were on the lines, with the blaze 50 percent contained. There have been Level 3 and Level 2 evacuation orders.

• The Cayuse Mountain wildfire 12 miles east of Tonasket was at 1,768 acres, with containment listed at 60 percent and full containment expected on Tuesday. Six homes have been threatened and 482 firefighters were on the lines on Sunday. “Essentially, we’re in good shape,” said Roland Emetaz of the state Department of Natural Resources.

• The Abraham Canyon wildfire five miles northwest of Inchelium was listed at 277 acres and 40 percent contained. There were 104 firefighters on the lines.

At the Northwest Coordination Center in Portland, Ore., public information officer Paul Ries expressed optimism on Sunday for the fire situation in Washington state for the coming week.

“The fire crews are pretty positive about getting on all these fires,” he said. “Weather conditions are expected to be cooler this week, which will help with any large fire potential.”

• Information from the Associated Press was included in this report.