Wildfires fueled by bone-dry brush and timber surged through Northern California forests on Friday, burning several homes and forcing thousands to flee mountain communities even as authorities prepared for a hot, crowded Fourth of July weekend that could bring the threat of new blazes.

Three wildfires near the towering Mount Shasta volcano an hour's drive from the Oregon border had burned around 50 square miles of land — a relatively small figure compared to sweeping, deadly fires of years past that blackened thousands of square miles.

But the blazes weren't anywhere near being surrounded as they continued to threaten homes in nearby areas.

"It is very hot and dry," said Suzi Johnson, a Shasta-Trinity National Forest spokeswoman for the Salt Fire, which broke out Wednesday and grew to 7 square miles (18 square kilometers), shutting several lanes of Interstate 5 and prompting evacuation orders for some roads in Lakehead, an unincorporated community of around 700 people.

A reporter for the Redding Record Searchlight saw at least a dozen buildings destroyed south of Lakehead, including homes, garages and outbuildings, the paper reported.

Tim Grubb used a hose on Thursday to wet down his wooden home in Lakehead as flames burned in the surrounding mountains.

"Real concerned," he said. "The winds coming up and the flames aren't too far away. So we got to pay attention."

Alexis Hohimer and her son, Michael, ended up at a Red Cross shelter in the city of Shasta Lake after authorities ordered their trailer park to evacuate early Thursday.

"I'm still pretty concerned," she said. "I left some cats there and it's an RV. So, you know, if it burned, I couldn't go to another park."

"So all we can do is hope and pray right now. Keep our fingers crossed," she said.

Fire officials told the Record Searchlight that the fire might have been started Wednesday afternoon by hot parts or pieces of a car on the interstate flying off and igniting dry brush.

No building damage was reported from two other northern fires, which erupted as California and the rest of the U.S. West was mired in a historic drought tied to climate change.

To the north, the Lava Fire burning partly on the flanks of Mount Shasta grew to nearly 31 square miles (80 square kilometers) and was 27% contained. Evacuation orders for some 3,500 people in or near the city of Weed remained in effect.

The steep, rocky terrain challenged nearly 1,300 firefighters battling the blaze, which was ignited by lightning last week.

To the northeast, the Tennant Fire that broke out Monday in the Klamath National Forest and forced evacuations grew to about 15 square miles (38 square kilometers). The fire was expected to advance north toward Oregon, and its cause was being investigated.