LOWER LAKE, CALIFORNIA: Triple-digit temperatures and gusty winds thrust Northern California into full-fledged wildfire season with several new blazes flaring up, forcing hundreds of people from their homes.

California's 14 large fires, mostly in the scorched northern half of the state, are pushing 7,000 firefighters to their limits as they battle flames amid drought, said Daniel Berlant, a spokesman for the California Department of Fire and Forestry Protection.

Dozens of fires started Wednesday, but Berlant said crews quickly corralled all but five of them.

"They only need a little wind to allow them to burn at an explosive rate," Berlant said.

People are to blame for most wildfires, but Berlant said California's drought provides the fuel to get the flames burning rapidly.

The California National Guard said Thursday that it is sending in a fleet of nine helicopters — Blackhawks, Chinooks and Lakotas — to back up Cal Fire crews. They'll douse flames with water, evacuate the injured, and move around firefighters and their equipment.

Guard Capt. Will Martin said the force supports Cal Fire each year, and hundreds of guardsmen will also be sent later in the fire season to back up crews on the ground.

HOMES DESTROYED

The biggest challenge for firefighters is a fast-spreading blaze in Lake County, 130 miles north of San Francisco. The fire started Wednesday, and within hours destroyed two homes and charred 15 square miles. It was only 5 percent contained early Friday.

At least 650 residents were chased from their homes as the blaze raged in hills covered in dense brush and oak trees and dotted with ranch homes. The fire is burning near Lower Lake, south of Clear Lake, a popular summer recreation spot.

A separate fire near the small town of Isleton in the Sacramento-San Joaquin River Delta burned six or seven mobile homes Thursday evening before firefighters got it under control, said Steve Cantelme, chief of the Sacramento office of Emergency Services.

Cantelme said the fire was out Thursday night but crews remained on the scene raking through debris to ensure that no hot embers could reignite it.

Video from KCRA-TV in Sacramento showed mobile homes engulfed in wind-whipped flames at a property called Korth's Pirate's Lair Marina. Owner Kande Korth said everyone got out safely.

FIRE LINES HOLDING

Crews battling a fire east of California's Napa Valley held their ground, keeping that blaze from jumping any more containment lines.

The fire, which has burned for more than a week, has charred nearly 12 square miles in Solano County. It spread beyond its containment line Tuesday in rugged, steep terrain baked by triple-digit temperatures.

At least 136 structures remain threatened, and more than 200 people were still under orders to evacuate their homes on Wednesday. It is 80 percent contained. Vineyards were not threatened.

FOOTHILLS FIRES

A small fire near Groveland, a stop-off point for travelers headed to Yosemite National Park, has forced evacuations, but state Highway 120 remains open. The 265-acre fire 20 miles from the park's entrance is 5 percent contained.

In a separate foothills blaze northeast of Sacramento, evacuation orders have been lifted for residents of 50 homes. The fire, which ignited Saturday, burned through more than 3 1/2 square miles and is about half contained.

BASS LAKE BLAZE

Residents of 200 homes in the Central California community of Cascadel Woods were ordered to evacuate Thursday. A wildfire burning near Bass Lake for several days spread overnight from 3 square miles to more than 5. It is 30 percent contained.

Authorities say a boy acknowledged starting the fire by playing with a lighter to burn pine needles in the dry Sierra Nevada. They say the boy faces criminal charges but remains out of custody because he and his family are cooperating.

IN THE FAR NORTH

At least three smaller fires in the far north that started Wednesday each prompted evacuations. Two in Shasta County, 130 miles south of the Oregon border, were more than half contained.