Southern California’s Alisal Fire is 50% contained

Part of the Alisal Fire burns in California's Las Flores Canyon on Friday afternoon.
CNN  — 

Southern California’s Alisal Fire, which earlier this week closed portions of US Highway 101 and the Union Pacific Railroad west of Santa Barbara, was 50% contained as of Saturday morning, fire officials said.

That’s an improvement from Friday morning’s 41%. The fire has burned about 17,200 acres since it started Monday afternoon, according to InciWeb, a US clearinghouse for wildfire information.

The closed portions of the highway and the railroad have since reopened.

The flames earlier this week also neared but missed the Santa Barbara area’s famed Reagan Ranch, known as the Western White House during the Ronald Reagan administration.

The majority of the fire’s recent growth has been on the western flank, toward the oceanside community of Gaviota, according to InciWeb. High temperatures and low humidity have contributed to the growth, it said.

California has had a devastating wildfire season that has been exacerbated by the climate crisis, which has been creating ideal weather conditions for fires to spark and expand. Extreme drought conditions in the area have made extinguishing fires harder.

More than 1,700 firefighters are working on the Alisal Fire, which started Monday afternoon and was pushed by winds over a summit and across Highway 101. The cause of the blaze wasn’t immediately known.

CNN’s Aya Elamroussi contributed to this report.