California’s Gann Fire Grows Explosively in Calaveras County, Forcing Mass Evacuations

By Orbis Weather Staff | August 6, 2026

A wildfire burning in the steep, brush-covered foothills east of Stockton has exploded in size over the past several days, destroying structures, injuring a firefighter, and forcing thousands of Northern California residents from their homes. The Gann Fire, burning in Calaveras County near New Hogan Lake, has become one of the state’s most significant active fires of the summer, prompting a local state of emergency and drawing a massive firefighting response.

Explosive Growth

The Gann Fire ignited Monday, August 3, near Hogan Dam Road and Gann Road outside Valley Springs, in the Sierra Nevada foothills northeast of Copperopolis. Its growth since then has been rapid and, at times, dramatic: the fire had burned roughly 3,759 acres with zero containment by Tuesday afternoon, nearly doubled to 7,052 acres with 10% containment by Wednesday morning, and continued climbing to 9,363 acres by Wednesday afternoon before reaching 10,373 acres and 19% containment as of CAL FIRE’s most recent report. Officials attribute the fire’s aggressive spread to the area’s steep, rugged terrain and heavy loads of brush and woodland fuel, which CAL FIRE spokesperson Ricardo Coronado said are making the blaze especially difficult to contain. Crews have also been conducting firing operations — deliberately burning out unburned fuel ahead of the fire’s path — to help establish control lines.

Evacuations and Emergency Declaration

The fire’s rapid advance prompted Calaveras County Sheriff Rachelle Whiting to proclaim a local state of emergency, a step that unlocks extraordinary emergency resources and lays the groundwork for requesting state or federal assistance if needed; the county’s Board of Supervisors must ratify the proclamation within seven days. Six zones remain under immediate evacuation orders — CCU-109, CCU-110-A, CCU-130-B, CCU-139, CCU-140, and CCU-147 — stretching from the northeastern side of New Hogan Lake to west of San Andreas, with roughly 1,473 residents ordered to leave. Several additional zones are under evacuation warnings, affecting another 1,400 or so residents. Two shelters have opened for displaced residents and their animals: one at the Valley Springs Veterans Memorial, which accepts small pets, and a large-animal shelter at the Calaveras County Fairgrounds in Angels Camp. Four major roads around the fire perimeter have been closed.

Damage, Injuries and Cause

Seven structures — a mix of homes, commercial buildings, and other property — have been destroyed by the fire, and one firefighter has been injured. CAL FIRE has determined the fire’s cause to be equipment use, and authorities have made an arrest in connection with the incident, though further details on the suspect have not been released.

Firefighting Response and Community Impact

More than 2,700 personnel are now assigned to the Gann Fire under CAL FIRE Incident Management Team 6, operating in unified command with the Calaveras County Sheriff’s Office — up from roughly 1,500 personnel earlier in the week as the fire grew. Crews are deploying dozens of engines and water tenders, helicopters, bulldozers, and hand crews to attack the fire from the air and ground. The smoke has reached into nearby communities: the Calaveras Unified School District closed all of its campuses on August 5 due to poor air quality, just days into the new school year, before reopening August 6 with modified outdoor activities. Superintendent Kassie Meeks said the safety of students and staff remained the district’s highest priority throughout the closure.

Orbis Weather will continue monitoring the Gann Fire’s containment progress and any changes to evacuation orders. Residents in Calaveras County should follow guidance from CAL FIRE and the Calaveras County Sheriff’s Office for the latest information.

Compiled from CAL FIRE, CBS Sacramento, KQED, the Calaveras Enterprise, and myMotherLode.com.