File:Smoke from the Oak Fire, Mariposa County, California (MODIS 2022-07-26).jpg

English: On July 22, 2022, a spark in tinder-dry vegetation near the town of Midpines, California ignited into an explosive blaze that has seared through grass, brush, and timber to become—in just three days—the largest fire in the state this year. On the evening of July 25, CALFIRE reported that the fire had burned 17,241 acres and had reached 16 percent containment. The fire also destroyed 21 single resident structures and 34 outbuildings. Midpines is a town of about 1,200 residents in Mariposa County, a Central California county in the Sierra Nevada foothills.

After initial explosive growth, with embers traveling more than a half-mile, CALFIRE summarized firefighting efforts on July 25 as “successful”, with minimal additional growth of the fire. Helicopters dropped 300,000 gallons of water on the fire on that day, and crews continued to construct fire lines to help control growth. The fire is reported to be moving towards the northeast, with spread slowed primarily to the eastern side of the fire. More than 2,400 structures are still considered at risk, and evacuation orders are in place in rural and residential locations in the path of the blaze. Thanks to firefighting efforts, some evacuation orders were changed to advisements, which are not mandatory.

On July 24, 2022, the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Aqua satellite acquired a true-color image of the Oak Fire as smoke poured from the blaze. The dense smoke stretched more than 245 miles (394 km) northward over the Sierra Nevada Mountains, nearly reaching Mount Shasta in Northern California. A large red “hot spot” marks actively burning fire.

Only 12 miles east of the Oak Fire, another difficult fire ignited on July 7. Known as the Washburn Fire, the blaze had threatened the Mariposa Grove of giant sequoias. The Washburn Fire had burnt 4,866 acres but, after aggressive firefighting, reached 87 percent containment on July 25. At that time, fire activity was low enough that fire crews focused on “mopping up” activities. According to InciWeb, mopping up occurs as firefighters seek out the remaining portions of heat near the control lines and extinguish them. This operation is critical to ensure all control lines are secure before firefighters are extracted by helicopter from the more remote portions of the fire.

While smoke from the Washburn fire undoubtedly mingles with the heavier plume created by the Oak Fire, the contribution seems to be small. There is also no visible hot spot to mark the location of the Washburn Fire, suggesting that most fire activity has been quenched.