The fire broke out in the area of Tenaja Road and Clinton Keith Road near the edge of the Santa Ana Mountains Wednesday around 4 p.m. when it was initially reported at 25 acres.
Over 800 personnel were assigned to battle the blaze, deemed the Tenaja Fire. The cause of the fire remains under investigation, but some lightning strikes had recently been seen in the area amid Wednesday's very hot and humid conditions.
Fire crews were working to the gain control of the flames, but were having difficulty accessing the fire in the "difficult terrain," authorities said at a Thursday evening press conference.
Shifting winds also made reigning in the fire a strenuous task, a unique weather pattern in the area known as the "Elsinore Effect," according to Cal Fire Division Chief Todd Hopkins.
"The winds will come out of one direction in the morning, to where the wind will be blowing out toward the ocean, and then by the afternoon, we'll get a 180 degree switch in the wind direction and the fire will tend to start burning downhill and start coming back into neighborhoods," Hopkins said.
The blaze was 10% contained by Thursday evening, officials said.
Six Cal Fire air tankers and three water-dropping helicopters made runs on the blaze, but pulled out by 8 p.m. Wednesday due to poor visibility. At least one air drop was ordered Thursday morning around 4:30 a.m.
Nearly 600 homes were evacuation area, though 141 decided to stay in place, Murrieta police said. Authorities issued mandatory evacuation orders for all residences along The Trails Circle in La Cresta. There was also an evacuation order issued for the Santa Rosa Plateau Visitor Center at 39400 Clinton Keith Road.
Residents in Copper Canyon, south of Calle del Oso Oro, between Clinton Keith and Murrieta Creek at Calle del Oso Oro were also under evacuation orders. Residents of several streets in the city of Murrieta were also forced to evacuate, including Montanya Place, Botanica Place, Belcara Place and Lone Oak Way.
Two structures sustained minor damage in the fire, officials said.
#TenajaFire [UPDATE] - Evacuation Orders have been issued for Montanya Place, Bonita Place, Belcara Place & Lone Oak Way in the city of Murrieta.— CAL FIRE Riverside (@CALFIRERRU) September 5, 2019
Also, all schools in the Murrieta Unified School District were closed Thursday, according to the police department.
Multiple school districts in the area announced they would close Friday.
All Lake Elsinore Unified School District schools will close for the day due to "Tenaja fire impacts on staffing, students and families."
All schools in the Perris Union School District, Romoland School District and Menifee School District will also be closed Friday, citing unhealthy air quality conditions.
EVACUATIONS: A map showing areas that are under mandatory and voluntary evacuations is available here.
Those who hadn't been ordered to evacuate were packing up their belongings and waiting to see how the fire would shift through the night.
"It's scary," said Bob Campini, a Murrieta resident. "We've packed up. We're waiting to see if we're going to get evacuated or not."
Some roads were also being shut down in the area.
A care and reception center was established for local residents at Murrieta Mesa High School, 24801 Monroe Ave. Small animals were accepted there. Larger animals can be brought to the San Jacinto Animal Shelter 581 S. Grand Ave. San Jacinto.
The wind was blowing west to east, creating heavy smoke over that part of Riverside County.