LOS ANGELES (KNX/AP/CNS)  -- Firefighters sought to gain more headway Tuesday into the wind-driven wildfire that began in Riverside County and spread to Orange, Los Angeles and San Bernardino counties, scorching more than 28,889 acres in three days, authorities said.

PHOTOS: North OC Fire

The blaze, which started near Corona in Riverside County about 9 a.m. Saturday, has destroyed or damaged 259 residences and continues to threaten about 1,000 homes, according to the Orange County Fire Authority.

More than 3,800 state, county and city firefighters remain assigned to the blaze, which has caused minor injuries to nine firefighters, according to fire officials.

By Monday afternoon, all evacuation orders were lifted in the Diamond Bar area, where some of the most intense battles against the blaze occurred, fire officials said.

Yorba Linda residents were also allowed to return to their homes Monday,
and officials from Yorba Linda Water District advised those living in the Hidden Hills Estates neighborhood to boil tap water at least five minutes before it is consumed.

Evacuations remained in effect Tuesday for the Carbon Canyon areas of Olinda Village and Hollydale Mobile Home Park in Brea, as well as the Carbon Canyon areas of Sleepy Hollow and Oak Tree Downs in Chino Hills, the OCFA reported.

Inspector Frank Garrido of the Los Angeles County Fire Department warned residents returning to their homes to be on the look out for snakes and other wildlife coming out of the forest area.

Placentia/Yorba Linda Unified and Walnut Valley Unified school district campuses are expected to reopen Tuesday.

But all public schools in the Brea-Olinda Unified School District will remain closed.

St. Francis of Assisi Catholic School in Yorba Linda was expected to remain closed, possibly through the end of the week.

St. Angela Merici Catholic School, Vineyard Christian Preschool & Elementary in Anaheim and Calvary Christian School in Yorba Linda were all closed Monday, and it was unclear if they would reopen Tuesday.

In Riverside County, as many as 600 homes were evacuated Saturday morning in Corona, within the Green River community, north of the Riverside 91 Freeway.

Seventeen homes were damaged or destroyed in the Dean Homes neighborhood before the blaze jumped three miles down the Santa Ana River Canyon, touching down in Anaheim Hills south of the river, and Yorba Linda north of it.

The fire eventually merged with a fire that broke out near Brea.

It was renamed the Freeway Complex Fire, then the Triangle Fire.

The cause of the blaze remains under investigation, said Riverside County Fire Department spokeswoman Kathleen Henderson.

KCAL9 reported that sparks from a vehicle on the Riverside 91 Freeway may have touched off a small fire in a tree next to the roadway, and fierce winds quickly spread the flames.

Damage assessment teams from the Orange County and Los Angeles County fire departments will continue to try and get a handle on the extent of destruction from the blaze, which has already cost more than $10 million to fight, fire officials told the Orange County Register Monday night.