The fire east of Sacramento had burned through 111 square miles (287 square kilometres), up from 44 square miles (114 square kilometres), yesterday as winds surged to 25 mph (40 kph) and continued to fuel its rapid expansion, according to the California Department of Forestry and Fire Protection. It was 5 per cent contained.
"This fire is definitely eye-opening," Cal Fire spokeswoman Alyssa Smith said.
The blaze, which began on Saturday, has been fueled by heavy timber and grass that is extremely dry because of California's third straight year of drought.
The blaze was burning about 20 miles (30 kilometers) from Desolation Wilderness, a popular hiking area south of Lake Tahoe.
Gov Jerry Brown declared a state of emergency late Wednesday, freeing up funds for the two fires. Brown also had secured federal grants to fight each of them.
Rain was possible in the area Thursday, though more gusty, erratic winds also were expected, and there was a chance of lightning.