The Big Grass Fire, burning along the southern Malheur County, Oregon, and Owyhee County, Idaho border near Jordan Valley, has cemented its place in the record books as the largest wildfire in Oregon's modern history. As of August 19, 2026, the fire has scorched an estimated 578,422 acres and is 71% contained — a hard-won milestone after weeks of round-the-clock suppression work by hundreds of firefighters.
A Season-Defining Event
The Big Grass Fire ignited during a period of extreme heat and drought across the high desert of eastern Oregon and southwestern Idaho, where dry grass and sagebrush provided ideal fuel conditions. The fire spread rapidly across the open terrain, overwhelming initial attack resources and quickly escalating to a Type 1 incident requiring a National Incident Management Organization (NIMO) team.
At its peak, the fire's growth prompted evacuations across a wide swath of rural Malheur County. Ranchers scrambled to move livestock, and highway closures disrupted travel along U.S. Highway 95 and adjacent ranch roads for extended periods.
Historic Scale
To put the fire's size in perspective, 578,000 acres is roughly the size of Yosemite National Park. The fire surpassed the previous record for Oregon's largest modern wildfire, a mark that has been rewritten several times in recent decades as climate conditions have intensified fire behavior across the West.
The fire has burned across a landscape of high desert grassland, sagebrush steppe, and juniper woodland — ecosystems that support imperiled sage-grouse populations and are home to many ranching operations that have operated for generations.
Progress and Ongoing Risks
Thunderstorms that swept through parts of Malheur County, Oregon, and Owyhee County, Idaho over the weekend sparked several new satellite fires near the main perimeter, temporarily complicating containment progress. Crews worked aggressively to keep those new ignitions from connecting with unburned fuel outside the main fire area.
Despite the challenges, firefighters have made steady progress on the southern and western flanks of the fire. The 71% containment figure, while promising, still leaves a substantial uncontrolled perimeter. Crews are focused on strengthening containment lines in areas with the greatest threat to structures and range resources.
Impacts on Rural Communities and Agriculture
The fire's impact on ranching in the region has been severe. Thousands of acres of grazing allotments on Bureau of Land Management and private lands have been burned, destroying fencing, water infrastructure, and forage that ranchers rely on to sustain their operations. Recovery efforts are expected to take years and will likely require federal assistance through programs administered by the Farm Service Agency and the Natural Resources Conservation Service.
For more information and daily updates on the Big Grass Fire, visit InciWeb at inciweb.wildfire.gov or contact the Oregon Department of Forestry.