Some personnel are being released from the Glass Fire in Napa and Sonoma counties as containment reached 90 percent Sunday morning, Cal Fire said in an update.
Personnel assigned to the fire stood at more than 1,200 Sunday and more than 2,000 structures remain threatened.
The fire has burned more than 67,000 acres and destroyed more than 600 single-family homes between the two counties since it broke out Sept. 27.
"There has been smoldering heavy fuels and minimal activity over the entire Glass Fire area," Cal Fire said.
"As residents are allowed to return to their homes, please drive carefully as emergency personnel are still working throughout the fire area. The demobilization of resources continues, resources are anticipated to be released based on the current fire and weather situation."
Crews expect to have the fire fully contained Oct. 20, Cal Fire said. No one has been injured or killed.