Tartar Fire at 41% Containment as Southwest IMT Takes Command Near Weiser, Idaho

The Tartar Fire burning in Washington County, Idaho, reached 41 percent containment on August 5, 2026, as Southwest Area Incident Management Team 1 assumed command of the incident from Great Basin Team 3. The fire, which has burned approximately 138,278 acres just north of the city of Weiser, remains one of the largest active fires in Idaho this season and continues to pose a threat to communities and infrastructure along U.S. Route 95.

How the Fire Grew

The Tartar Fire ignited in late July and initially spread through rangeland and sagebrush north of Weiser. The fire's most dramatic growth came during the early August wind event that swept the Northwest region, when the fire ran approximately 20 miles toward Weiser over a matter of hours. As the fire moved south toward the city on the morning of August 2, hay bales along Water Tank Road ignited, and outbuildings near U.S. Route 95 were impacted.

The fire's northwestern edge was also tracked closely for potential merger with the adjacent Fox Fire, which would have significantly expanded the incident's geographic footprint and complicated suppression strategies. Firefighters and aircraft worked aggressively to prevent that merger.

Current Containment Progress

Since the initial explosive growth, firefighters have made steady progress on the Tartar Fire's more manageable flanks. Crews increased containment along the southern and eastern edges of the fire near Olds Ferry Road and north of Weiser, assisted by local partners and aerial resources. The newly assigned Southwest Area IMT 1 is shifting the strategic focus to the fire's western flank, which remains the most active portion of the perimeter.

Aircraft support, including airtankers and helicopters, has been essential in slowing fire spread in areas where ground crews cannot safely access the terrain. The Brownlee Reservoir area along the Idaho-Oregon border has provided a natural barrier that firefighters have been working to reinforce.

Evacuation Status

Level 3 (Go Now) evacuation orders remain active for portions of Washington County north and west of Weiser. Residents in these areas are urged to remain out until official clearance is given by Washington County emergency management. Level 2 (Be Ready) warnings extend across adjacent areas where conditions could change rapidly.

Local agricultural operations have been significantly affected, with livestock evacuations ongoing in the affected zones. The Idaho Office of Emergency Management has been coordinating with county officials on resource support for displaced residents and farmers.

Fire Statistics

Size: 138,278 acres
Containment: 41%
Location: Washington County, Idaho — north of Weiser
Cause: Under investigation
Incident Management: Southwest Area Incident Management Team 1
Primary fuels: Sagebrush, rangeland grasses, agricultural lands

What to Watch

Fire managers are closely watching weather forecasts for additional wind events that could challenge containment lines on the western flank. Crews are working extended operational periods to take advantage of cooler morning temperatures and higher relative humidity before afternoon conditions deteriorate.