Some areas are still inaccessible to search crews, who must wait for the ground to dry out, Brown said.
The day before the storm hit on Jan. 9, authorities spent hours roving the community's foothill neighborhoods, trying to persuade people living near fire-ravaged slopes to leave.
About 7,000 people living north of Highway 192 were under mandatory evacuation orders.
Voluntary orders were issued for 23,000 others as the storm approached. Residents in those areas were not visited by sheriff's deputies, officials have said.
The death toll increased to 21 Saturday morning after search crews recovered the body of 28-year-old Faviola Benitez Calderon.
Benitez Calderon is the fourth member of her family confirmed to have died in the mudslide, caused by heavy rain on hillsides destabilized by the Thomas fire, the largest in state history.
"This family has lost so much, and we wish them our best as they face the difficult journey of trying to move forward without their loved ones," Brown said.
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