A Solano County fire dispatcher said on Wednesday that there were still some visible flames, but that units had been cleared and the command terminated.
The U.S. Coast Guard evacuated at least four people from the island, which is only accessible by boat.
The brush fire started Tuesday and quickly grew as winds fanned the flames.
Officials said there are 20 buildings on the island just north of Antioch near the Contra Costa, Solano and Sacramento County borders.
The Santa Anas, generated by strong surface pressure anchored over the West, were predicted to remain at advisory levels until noon Wednesday. Red-flag warnings for fire danger were expected to remain in effect until Wednesday evening.
In Southern California, flames were spread by 25 mph winds across a 2-acre property in Riverside County's Jurupa Valley and destroyed two houses, two mobile homes, three motor homes, 40 vehicles in different states of repair and about a dozen small structures, state fire Capt. Lucas Spelman said. Two more mobile homes were damaged.
Alejandro Heredia fled with his 3-year-old child, 15-day-old baby and dog when palm trees began burning in a field behind his home. He said firefighters concentrated on saving his parents' nearby house while his burned.
"We asked for help, and they said that they were doing what they can," Heredia told the Riverside Press-Enterprise. "Everything is lost. There's nothing left."
Deputies ran back into one smoke-filled house that had been evacuated to save a litter of shar-pei puppies when they feared that their owner, who was found crying in the evacuation area, was about to head back in herself, sheriff's Sgt. Red Heard said.
Two deputies came out of the house with the 20-week-old puppies in their arms, but the dogs' parents couldn't be found after the blaze.
"How are they going to survive without their mom?" the 19-year-old owner Carla Guardado told the Press-Enterprise.
By nightfall, 110 firefighters had the fire fully contained.
"The reason why we got an upper hand so quickly is because the wind had actually subsided for about 10 minutes," allowing a breathing space for firefighters, Spelman said.
In Los Angeles, a SuperScooper aircraft dumped tons of water on streams of flame that rolled up a steep cliff side along Pacific Coast Highway in Pacific Palisades on Tuesday afternoon. The flames crept within feet of multimillion-dollar cliff-top homes, but none were damaged.
The fire was knocked down in about 1 1/2 hours, but the highway remained closed for several hours more until one lane opened in each direction.
Earlier, more than 100 firefighters and two helicopters responded when a large house caught fire in the Chatsworth area of the San Fernando Valley and strong gusts threatened to spit embers into a neighborhood downwind.