WILLOWS (AP) — A series of burgeoning wildfires in Northern California was threatening 23 homes and has forced residents to leave the area as a precaution, officials said Friday.

More than 1,200 firefighters were battling the Colusa County blazes, known as the Sixteen Complex. The fire has grown to more than 19 square miles since it ignited Tuesday and was 20 percent contained on Friday, CalFire spokeswoman Stacie McCambridge said.

Crews were working aggressively to establish containment lines through grass, brush and oak woodland in steep and rugged terrain, McCambridge said.

An evacuation advisory was also in effect for the Cortina Indian Rancheria near Highways 16 and 20 as firefighters worked to preserve structures on the reservation, CalFire spokesman Daniel Berlant said.

A stretch of roadway from Highway 20 to the town of Rumsey was also closed. Fire officials hoped to have the blaze fully contained as early as Monday, but winds could pick up over the weekend and hamper containment efforts, Berlant said.

The Sixteen Complex Fire was among a handful of fires actively burning in Northern California.

Residents from three neighborhoods in Trinity County left their homes Thursday as the Stafford fire spread. Nearly 350 firefighters were on the scene at the 3 acre blaze outside of Hayfork, which was 15 percent contained, fire spokesman Don Ferguson said Friday.

"The community appears to be pretty calm for the most part and we feel like nothing major is going to happen," Ferguson said. "We just need them to be out of the way for the sake of safety as we try to get this thing under control."

Ferguson said Friday could be a pivotal day as crews have circled around two-thirds of the fire with plans to complete several intentional burnouts to curb further spreading. He anticipates the containment total to spike significantly in the next couple of days.

"We're hoping that this one won't last long," Ferguson said.

Meanwhile, a weeks-old fire in rugged and remote Mendocino County is now 72 percent contained after scorching more than 65 square miles.

More than 900 firefighters have maintained their containment lines as the North Pass fire was expected to reach full containment by Monday, officials said.

Approximately 26 structures have been destroyed since the blaze northeast of Covelo caused by lightning strikes began burning on Aug. 18.