The fire was about 35 percent contained and was not expected to be under control until next week, fire officials said. It has burned nearly 6 square miles and destroyed 38 structures. Another 570 buildings were threatened.
Almost 2,000 residents remained under evacuation orders - more than 450 of them mandatory - while more than 3,000 personnel and a swarm of air tankers, helicopters and fire engines were deployed to the area, said Dave Shew, a battalion chief with the California Department of Forestry and Fire Protection. Four firefighters suffered minor injuries.
"As long as we don't have this fire contained, then the homes are still threatened," Shew said. "We don't consider this to be anywhere near contained. I wouldn't say we're out of the woods yet."
Smoke from the wildfire left a haze over the San Francisco Bay area that was expected to linger through the Memorial Day weekend.
Gov. Arnold Schwarzenegger declared a state of emergency in Santa Cruz County on Friday to allow access to funds for the effort. On Saturday issued a similar declaration for Santa Clara County after the fire jumped over into that county, burning what fire officials estimated was less than 300 acres there.
Officials were investigating the cause of the fire, which was first reported Thursday morning in the mountain range that separates Santa Cruz and Santa Clara counties. The area, about 15 miles south of San Jose, is rural but dotted with homes.
"I feel a great sadness in my heart for everybody who is involved in this event," said Kenneth Rich whose house was destroyed. "It's devastating."