July The Mendocino Complex comprised two vegetation fires that burned within miles of each other near
Clear Lake, in
Northern California. The first of the two fires reported was the Ranch Fire, which was reported on July 27, 2018, at 12:05 PM PDT, off
Highway 20 near
Potter Valley. Within hours of being reported, the fire had injured two firefighters. Approximately one hour later, the River Fire was reported on Old River Road, six miles north of
Hopland, located south of the Ranch Fire. By the evening, the River Fire had burned and destroyed two buildings, including a home. The fire threatened the
University of California Hopland Research and Extension Center. High heat, low humidity, and rugged terrain challenged control of the fires, with gusty winds causing both to grow. Overnight, five more firefighters were reported injured. By the next morning, the two fires were organized under the "Mendocino Complex" name. The River Fire had grown to , the Ranch Fire had burned , and both were at two percent containment, with 386 structures being threatened. With
Red Flag Warnings in effect, the first mandatory evacuations began in Hopland and with residents along
Highway 175.
Mendocino College was named an evacuation center. By the afternoon, the community of
Lakeport and additional areas of
Lake County were placed under mandatory evacuation and, later that evening, Potter Valley and parts of
Upper Lake were evacuated. By the morning of July 29, three more structures had been destroyed, all houses. Dry and windy conditions persisted, and the lack of available firefighters due to other fires burning in the state slowed attempts at containment. The communities of Witter Springs,
Finley,
Saratoga Springs,
Nice, Bachelor Valley, Scotts Valley, and
Big Valley Rancheria were evacuated. The fires rapidly grew overnight, with the Ranch Fire totaling and the River Fire reaching by the morning of July 30, with the fires at 10 percent containment. Later in the afternoon of July 30, evacuation orders were lifted for Hopland, the Hopland Rancheria, and the area just north of Largo, while evacuation orders were put in place for
Kelseyville and
Finley. Containment of the fire declined to five percent as the fires grew in size. One more home was destroyed and one damaged. Evacuation orders were lifted for Potter Valley in the afternoon of July 31. By the evening of July 31, the fires had burned a combined total of and were 12% contained.
August The two fires continued to burn into August, with the Ranch Fire at and the River Fire at on August 1. The Ranch Fire remained at 15 percent containment, while the River Fire was at 38 percent containment. Containment line improvement remained the focus of fire crews, with some crews directly fighting the fire when conditions permitted. Additional crew support arrived from the US Forest Service. Throughout the day, both fires grew, with the Ranch Fire burning into the
Mendocino National Forest and south of
Lake Pillsbury. Overnight, the fires remained most active in higher elevations. By the morning of August 2, the two fires had burned a combined total of and were 39 percent contained. Mandatory evacuations were put in place in Western Lake County, particularly for areas west of
Lucerne and north of
Clear Lake. On the evening of August 4, the combined acreage was 229,000 acres. By the morning of August 5, the combined acreage was , with 152 buildings destroyed. On the morning of August 6, the combined acreage was , with 169 buildings damaged or destroyed. By the night of August 6, the combined acreage of the Mendocino Complex Fire was , thus surpassing the
Thomas Fire to become the largest wildfire complex in modern California history. On August 7, 2018, officials announced that they predicted the Mendocino Complex would last through August and into early September, compared to the earlier prediction of mid-August. By then, the fire complex had destroyed 143 structures, 75 of them residences. By late August 7, the fire complex was 34% contained. Of the two fires, the Ranch and River Fires, the River Fire was 78% contained, while Ranch Fire was only 20% contained, with flames on the northern flank still pushing towards
Snow Mountain Wilderness. By the night of August 7, the combined acreage was , with 169 buildings damaged or destroyed. By the morning of August 8, the fire had destroyed 221 buildings, while damaging another 27. By Wednesday morning, on August 8, 2018, the Mendocino Complex Fire had burned and was 47% contained. Cal Fire estimated that containing the entire fire complex could take until September 1, over a month after it ignited on July 27. By Thursday, August 9, 2018, the total area burned had grown to 302,086 acres. By Saturday morning, on August 11, 2018, the Mendocino Complex Fire had burned , was 67% contained, and had destroyed 258 buildings. On the morning of Sunday, August 12, the Ranch Fire grew to and was only 62% contained, surpassing the
Thomas Fire as California's single-largest modern wildfire. Meanwhile, the River Fire remained at , with 93% containment, with the Mendocino Complex Fire having burned a total of . During the evening of Monday, August 13, the River Fire was fully contained at , leaving the Ranch Fire as the only active fire within the Mendocino Complex. However, the larger Ranch Fire continued to expand. By the evening of August 14, the Ranch Fire had grown to , with only 64% containment, increasing the size of the Mendocino Complex Fire to , with a collective containment of 64%. Around that time, it was reported that the Ranch Fire had killed a firefighter from
Utah. this allowed the Ranch Fire to surpass the size of the massive
Rush Fire in 2012, which burned across California into Nevada, By the morning of August 18, the Ranch Fire had reached , with 76% containment, increasing the size of the Mendocino Complex Fire to . August 19 was a day of chaos wherein LAFD firefighters were surrounded and had to scramble through the forest to safety. A firefighter was flown to a
burn center and another four were treated for burns. Another firefighter was treated for a
dislocated shoulder. On August 28, the Ranch Fire reached and was at 93% containment, increasing the Mendocino Complex Fire's burn area to . On the same day, it was reported that the Ranch Fire had stopped its forward spread.
September On September 1, InciWeb updated the Ranch Fire's size to , with 96% containment, as the fire burned through previously unburned areas in interior regions, increasing the burn area of the Mendocino Complex Fire to . Afterward, the Ranch Fire stopped growing, with containment of the Ranch Fire increasing to 98% by September 4. During the next couple of weeks, containment of the Ranch Fire remained at 98%, without any further growth in size, as the fire continued burning deep within the fire perimeter, within the northern portion of the burn area. On September 19, the U.S. Forest Service reported that the Ranch Fire had been fully contained during the evening of September 18, bringing both of the fires in the Mendocino Complex to full containment. However, InciWeb stated that the Ranch Fire was not out yet, as hotspots continued to smolder deep within the containment lines of the fire.
October – January Hotspots continued to persist within the perimeter of the Ranch Fire for another few months. On November 7, 2018, InciWeb stopped issuing updates on the Mendocino Complex and declared the incident to be inactive. On January 4, 2019, Cal Fire reported that the Mendocino Complex had fully been brought under control, extinguishing the fire 160 days after it had started. ==Effects==