Firefighters struggle against wildfires in California, western US

Wildfires across the Western United States continued to grow as firefighters struggled to contain them. 

The Dixie fire in Butte and Plumas counties was 15% contained and had increased in size by 50%, up to 96 square miles, as of Wednesday, CalFire said. 

People in parts of Butte and Plumas counties were ordered to evacuate as the fire threatened 800 homes and businesses. 

Firefighters had difficulty determining when the fire can be fully contained due to the size of the fire and the rugged terrain, fire crew said. 

SEE ALSO: PG&E says its equipment may be linked to massive Dixie Fire

In Alpine County, firefighters were expecting full containment of the Tamarack fire later next week. 

The fire was started by lightning on July 4 and forced parts of Highway 88 and 89 to shut down. 

Mandatory evacuation orders remained in effect. 

SEE ALSO: Bootleg fire: Dangerous 'fire clouds' form over Oregon

The Bootleg fire in Southern Oregon, which was also started by lightning more than two weeks ago, was 32% contained as of Wednesday, fire crew said. 

The fire had burned 606 square miles, bigger than the size of San Francisco and Marin County combined. 

The fire may not be fully contained until the rainy season begins in a few months, officials said. 

This story was reported from Oakland, Calif.