More than 51,000 acres have been consumed by the McKinney wildfire in northern California, forcing the evacuation of thousands of residences and triggering an emergency in one county.

The California Department of Forestry and Fire Protection (Cal Fire) stated that 51,468 acres had been consumed by fire, with zero percent containment.

The wildfire is expanding in Siskiyou County, the northernmost county in California bordering Oregon and the location of Klamath National Forest, where the majority of the fire is burning.

Gov. Gavin Newsom (D) issued a state of emergency in Siskiyou County on Saturday. The McKinney Fire grew into the year's largest wildfire in California and sent ash into the stratosphere.

According to Newsom, the Friday-started McKinney Fire was "intensified and spread by dry fuels, extreme drought conditions, high temperatures, winds and lightning storms."

The wildfire has burned homes and caused nearly 2,000 families to evacuate.

It also mingled with two more fires over the weekend, the China 2 and Evans fires, forcing an additional 200 residents to evacuate.

According to the National Park Service, the region remained under a red flag warning on Sunday, with the potential for dry lightning and strong winds to intensify the blaze.

The Oak Fire, which has destroyed about 20,000 acres of land in Mariposa County and was 64 percent contained as of Sunday, is already being fought in California.