After weeks of explosive growth that made it the largest wildfire in Oregon history, the Big Grass Fire burning along the Oregon-Idaho border near Jordan Valley has reached 94 percent containment as of September 7, 2026. Crews are now in mop-up and patrol operations as fire managers work to bring the historic blaze to full containment.

The fire, which ignited naturally on July 23, ultimately burned 578,637 acres of short grass and rangeland across Malheur County, Oregon and Owyhee County, Idaho — a swath of high desert roughly the size of Rhode Island. At its peak, the Big Grass Fire burned across some of the most remote and wind-exposed terrain in the interior West, with fire behavior driven almost entirely by wind-driven runs through cured grasses in temperatures exceeding 100 degrees Fahrenheit.

A Record That Will Stand for Years

When the Big Grass Fire grew past previous records, it rewrote Oregon's fire history books. The fire surpassed the previous state record by a considerable margin, becoming the benchmark against which future seasons will be measured. Its sheer scale — nearly 580,000 acres — placed it among the largest wildfires recorded in the continental United States in recent decades.

Unlike many of Oregon's most destructive fires, which have burned in the forested Cascades or dense timber of southwestern Oregon, the Big Grass Fire burned primarily through sagebrush-steppe and short-grass rangeland in the state's arid southeastern corner. This distinction matters: grass fires spread faster, produce less intense heat, and are generally more containable than timber fires — but the scale and speed of this blaze still overwhelmed initial attack resources and required a massive interagency response.

Owyhee County Evacuation Orders Lifted

A Level 3 "Go Now" evacuation order that had been in effect for portions of Owyhee County, Idaho, was lifted as containment improved in recent days. Residents who had been displaced from ranches and rural properties along the fire's Idaho flank have been cleared to return, though road and trail closures may still be in effect in some areas pending final safety assessments.

In Malheur County on the Oregon side, structural threat to the widely scattered ranching operations near Jordan Valley prompted significant concern early in the fire's run, with fire officials working to protect isolated ranch infrastructure as the fire burned across vast rangeland. The low population density of the region ultimately limited direct structural losses compared to what a similar-sized fire would cause in more developed terrain.

Suppression and Resources

At its peak, the Big Grass Fire was supported by hundreds of firefighters, multiple fixed-wing aircraft, and helicopter resources drawn from across the western United States and Canada. The incident was managed under a Type 1 Interagency Hotshot Team configuration, with multiple operational periods requiring extensive aviation support for spotting, reconnaissance, and suppression drops along exposed flanks.

Looking Ahead

With 94 percent containment achieved, fire managers expect to reach full containment within days, barring any significant weather event. Mop-up operations — the labor-intensive process of extinguishing any remaining heat within the fire perimeter — are ongoing along the fire's edge, with patrol crews monitoring for any spots or escapes.

  • Current containment: 94 percent (as of September 7, 2026)
  • Total acreage: 578,637 acres
  • Location: Jordan Valley area, Malheur County, OR / Owyhee County, ID
  • Cause: Natural ignition (lightning)
  • Fire type: Short grass / sagebrush rangeland

The Big Grass Fire will remain a defining chapter in Oregon's fire history — both as a record-breaking event and as a case study in how climate-driven drought and heat can transform vast stretches of high desert into fuel for catastrophic fire.