ACTON, Calif. (Reuters) - Thousands of California residents were allowed to return home on Monday after a deadly, destructive wildfire forced them from their houses in recent days as it raged through drought-parched canyons and foothills north of Los Angeles.

About 300 miles (480 km) to the north, though, another fire ravaged a hilly area near the scenic coastal city of Carmel-by-the-Sea, churning through 16,100 acres (6,500 hectares) and destroying 20 homes and two outbuildings, authorities said.

The so-called Soberanes Fire, burning in the Los Padres National Forest in Monterey County, threatened 1,650 structures by Monday evening and was only 10 percent contained, the U.S. Forest Service said.

Near Los Angeles, a beefed-up force of nearly 3,000 firefighters battled to outflank the blaze there - known as the Sand Fire - which has charred at least 50 square miles (130 square km) on the rugged northwestern fringes of the Angeles National Forest, authorities said.

The Sand Fire erupted on Friday and also remained just 10 percent contained on Monday evening as crews backed by bulldozers labored to hack buffer lines around its perimeter.

The majority of the estimated 20,000 to 30,000 people who lived in the 10,000 homes that were evacuated earlier were allowed to return home on Monday evening, fire officials said.

Fed by dense brush left desiccated by five years of drought, flames were initially stoked by triple-digit heat and extremely low humidity. Slightly cooler, moister weather and diminished winds were expected to assist firefighters on Monday.

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“We have very little wind, we have an increase in relative humidity, and so it’s favorable for us to get out and to put out hot spots and work on line construction,” Los Angeles County Fire Chief Greg Hisel said. He said calmer winds were helping to keep the fire stationary.

The Sand Fire blaze was concentrated near the town of Acton, about 50 miles (80 km) north of Los Angeles, as it cast a pall of smoke and soot over a wide area. Much of the Los Angeles basin was dusted with a thin layer of fine white ash from the fire on Saturday and Sunday.

At least 18 dwellings were destroyed over the weekend, and authorities have reported one fatality, an unidentified man found on Saturday evening in a burned-out car parked in the driveway of a home.

Among the properties to go up in flames was the landmark Sable Ranch, a popular location for television and movie shoots.

The causes of the two fires were under investigation. They are among some 3,750 blazes large and small to have erupted across California since January, a higher-than-normal total, collectively scorching more than 200,000 acres (80,940 hectares), state fire officials said.

The biggest so far was last month’s Erskine Fire, which consumed 48,000 acres (19,429 hectares) northeast of Bakersfield, killing two people and destroying about 250 structures.

By comparison, the 2003 Cedar Fire ranks as the biggest on record in the state. It blackened more than 273,000 acres (110,480 hectares), leveled 2,820 buildings and claimed 15 lives.

(This story has been refiled to fix typo in lead)