Fueled by dry conditions and 20 mph gusts, the Sand Fire quickly spread to at least 1,500 acres with 0 percent containment by late afternoon.
County fire officials at one point had estimated the size at 2,500 acres, but later revised that downward to 1,500.
Evacuation orders were in effect for homes in the Soledad Canyon along the 14 Freeway to Agua Dulce Canyon Road.
The Red Cross opened an evacuation shelter at Golden Valley High School, 27051 Robert C. Lee Parkway, Santa Clarita.
No damage to people or property was reported yet.
*Update #SandFire evac from Soledad Canyon at 14 FWY all the way up to Aqua Dulce Canyon Road.— LACounty Fire PIO (@LACoFDPIO) July 22, 2016
The blaze started around 2:38 p.m. at about five acres, then grew quickly in size as it burned uphill, according to authorities.
Ground crews worked through rugged and steep terrain. At one point, the 14 Freeway was closed down, but it was quickly reopened.
Temperatures hit the triple digits by the early afternoon and the area is hit with about 20 mph winds.
Air tankers and helicopters dropped water as the blaze ate through the dry fuel along the hillsides. Huge plumes of smoke were visible throughout the Los Angeles region.
DEVELOPING: We will add more details to this report as soon as it becomes available.