TWISP, Wash. >> Thunderstorms dropped heavy rain on areas of north-central Washington hard-hit by wildfires this summer, triggering flash floods and mud slides Thursday night that damaged some homes, blocked portions of at least three highways and stranded some motorists, officials said.

There were no immediate reports of injuries.

Okanogan County Sheriff Frank Rogers said he heard “a couple” of homes along State Highway 153 near Twisp were damaged. Deputies were trying to reach the residences.

By late Thursday night, the rain was easing, the sheriff said.

Five to 12 vehicles were marooned on Highway 153 by mud and slides, Washington State Patrol Trooper Darren Wright said. Troopers and sheriff’s deputies worked late Thursday night to get the people out and leave the cars temporarily.

Mud and debris prompted the temporary closure of an eight-mile stretch of Highway 153 and a 25-mile section of State Highway 20, both in Okanogan County, the state Transportation Department said.

Wright said a small mudslide in nearby Douglas County blocked U.S. Highway 97 south of Chelan.

While the Carlton Complex wildfires that burned across more than 400 square miles are in mop-up stage, about 500 people are still assigned to fight them and nearby wildfires. Flash flooding and strong winds hit the Carlton fire camp and incident command post Thursday night, the National Park Service reported. All workers were accounted for and reportedly had dry places to sleep.

More than an inch of rain was reported in one hour near Twisp in an area burned by the Carlton Complex fires, National Weather Service meteorologist Matthew Fugazzi said.

“In those burned-out areas, every time we get a heavy rain” the flash flood risk exists, Rogers said. With the vegetation burned off the ground, “there’s nothing to hold it, the water just sloughs off.”

Members of Washington state’s congressional delegation have asked the federal government to reconsider a decision denying help for individuals affected by the huge summer wildfires.

More than 300 homes have been destroyed by the wildfires in north-central Washington, and Gov. Jay Inslee has said the cost of destroyed properties in Okanogan County alone is estimated at more than $28 million.

President Barack Obama has approved federal assistance for Okanogan County and the Colville confederated tribes to help repair or replace public infrastructure lost in this summer’s wildfires. The assistance approved means FEMA will reimburse Okanogan County and the Colvilles for 75 percent of the costs of eligible expenses related to disaster-damaged facilities such as roads, bridges, and public utilities.

But in a letter sent Wednesday to Federal Emergency Management Agency Administrator Craig Fugate, Sens. Patty Murray and Maria Cantwell and Reps. Doc Hastings and Dave Reichert urged the agency to review a decision that kept individual federal aid from people who lost homes or needed other help in Okanogan and Chelan counties.