The Tartar Fire, burning near Weiser in Washington County, Idaho, has grown to more than 107,825 acres and reached 16 percent containment as of August 4, 2026, making it one of the largest active fires in Idaho this season. The fire made a dramatic and destructive 20-mile run toward Weiser on the night of August 1-2, threatening structures along U.S. Route 95 — Idaho's primary north-south highway — and prompting Level 3 evacuation orders for portions of the Weiser area.

Timeline of the Run

The Tartar Fire's explosive run toward Weiser occurred during the same extreme fire weather event that spawned multiple large fires across the Pacific Northwest. Wind-driven flames pushed across rangeland at high speed, impacting structures along the US-95 corridor. The Adams County Sheriff's Office confirmed US-95 was closed at Midvale-Hale from mile marker 94 to Park Street in Weiser — a critical closure on a route that serves as a vital transportation artery for southwestern Idaho.

The Weiser Valley Roundup Rodeo Grounds were opened as a large animal evacuation point, allowing residents to bring horses and livestock as they fled the area. Multiple firefighting resources from neighboring areas were dispatched overnight to support structure protection and hold the fire perimeter along the highway corridor.

Firefighting Operations

By August 3, firefighters had constructed dozer lines near the Mann Creek Reservoir area and were using natural barriers, roads, and ridgelines to anchor containment efforts. The priority objective was to protect the Weiser community and hold the fire perimeter along the US-95 corridor. Aerial resources supported ground crews with retardant drops on the most active flanks.

US-95 has since been reopened to traffic, though some local roads in the fire area remain closed. Evacuation orders have been partially reduced as crews establish better control around the community, though residents should continue to monitor the Adams County Sheriff's Office for the latest status updates.

Context: Idaho's Active Fire Season

Idaho currently has seven active large fires, the most notable including the Tartar Fire, the Big Rock Fire (2,204 acres, 20 miles east of Idaho Falls), the Cascade Fire on the Nez Perce-Clearwater National Forest, and the Doublesprings Fire on the Salmon-Challis National Forest. Statewide fire danger remains at extreme levels across southern Idaho rangelands.

  • Tartar Fire size: 107,825 acres
  • Containment: 16%
  • Location: Washington County, near Weiser, ID
  • US-95: Temporarily closed; now reopened
  • Evacuation level: Level 3 (now partially downgraded)

For current fire information and evacuation status, contact the Adams County Sheriff's Office or visit InciWeb for the Tartar Fire incident page.