The "Walker" and "Wye" fires have burned 7,934 acres since they started around 4 p.m. Sunday. Full containment is expected by Monday.
Cal Fire has been referring to both fires as the Wye fire because they are under one management plan. There were 1,219 firefighters, 157 engines, eight helicopters and two air tankers at the fires Wednesday morning.
The Wye fire started near the intersection of Highways 20 and 53, and the Walker fire started a few miles further east.
The fires have destroyed two residences, an outbuilding and damaged two residences, Cal Fire said. There have been three injuries.
The threat to structures in the Wilbur Springs area has been reduced and remaining evacuations were to be lifted Wednesday morning.
The California Highway Patrol is escorting traffic along one lane of Highway 20 from Highway 53 to Highway 116 at Wilbur Springs, and firefighters hope Highway 20 will open to all traffic by Wednesday evening, Cal Fire said.
The cause of the fires is under investigation.
The American Red Cross is accepting donations to help people affected by the fires in Lake County. Visit www.redcross.org, call 1-800-RED-CROSS, text REDCROSS to 90999 to make a $10 donation or mail donations to American Red Cross, Sonoma, Mendocino and Lake Counties, 5297 Aero Drive, Santa Rosa, CA 95403 or to the American Red Cross, P.O. Box 37243, Washington, DC 20013.