Updated

Fire crews in Northern California turned their attention to a blaze in the Santa Cruz Mountains that has destroyed one home and is threatening hundreds of others.

The shift in focus came after gaining ground against a wildfire near a geothermal power producing facility in Sonoma County, officials said.

Firefighters working against the blaze in Sonoma County were sent to Santa Clara County after making progress against a 2 square-mile blaze burning near The Geysers, said California Department of Forestry and Fire Protection spokesman Scott McLean.

Evacuation and road closure orders were lifted Monday evening after fire crews increased containment to 45 percent, McLean said.

"It's looking very good but we still need to make sure smoke and small fires inside the perimeter are taken care of," he said.

The fires drew strength from an autumn heat wave but fire officials said they were hopeful cooler temperatures and higher humidity expected overnight would help stymie their progress.

"High temperatures and low humidity is a recipe for these fires to spread rapidly but we're looking for favorable weather throughout the night to help slow them down," McLean said.

The fast-moving wildfire in the Santa Cruz Mountains had charred 500 acres by Monday night and forced evacuations, though McLean didn't know how many houses had to be emptied.

Cal Fire Stephanie Stuehler said earlier that 300 homes had been evacuated.

The blaze started Monday afternoon on the southern edge of Santa Clara County. It was also threatening television and radio towers.

The wildfire in Sonoma County that erupted Sunday amid hot, dry conditions and gusty winds forced the temporary evacuation of one of its 14 geothermal plants.

Brett Kerr, a spokesman for Calpine, which operates The Geysers geothermal complex, said evacuated employees were allowed to return to the plant, which started operating later Monday.

All employees were safe and accounted for and the flow of electricity from the facility was not disrupted, he said.

"Our remaining plants at the Geysers continue to operate normally and our team is constantly assessing the situation and will take all steps necessary to ensure the safety of employees and the preservation of our facilities," Kerr said in an email.

The blaze near the small city Cloverdale has charred about 1,500 acres, or more than 2 square miles of timber and dry brush.

The Geysers are located in the Mayacamas Mountains and are naturally occurring steam field reservoirs below the earth's surface. They are harnessed by Calpine to make renewable energy for homes and businesses across Northern California, according to the company web site.

The site says The Geysers, spreading 45 square miles along the Sonoma and Lake County border, is the largest complex of geothermal power plants in the world. Calpine owns and operates the 14 power plants at The Geysers, providing power for the equivalent of 725,000 homes, according to the site.

The heat wave that baked even coastal cities that normally benefit from the cooling influence of the Pacific Ocean was expected to start easing Tuesday.

The mercury shot up into triple digits in downtown Los Angeles and points north and south as high pressure gripped the drought-stricken state. Most other areas were in the 90s or at least the 80s.