"The SISI fire’s rapid expansion to nearly 4,000 acres and sustained 15% containment highlight the challenges of managing large, naturally ignited wildfires in remote wilderness areas, underscoring the need for substantial firefighting resources and long-term suppression strategies."
The SISI wildfire, located 10 miles northwest of Stehekin in Chelan County, Washington, was first discovered on August 14, 2026. The fire, caused by natural factors and managed by the U.S. Forest Service, grew rapidly from 50 acres on August 21 to 3,908 acres by September 22, with containment remaining at 15% throughout the period. Early reports noted active group torching and spotting, while later updates described moderate creeping, flanking, and backing behavior. Personnel numbers increased from 13 on August 24 to a peak of 150 on September 9, reflecting the escalating effort to control the expanding blaze. Estimated costs rose from $198,414 in early August to $5,764,284 by September 22, mirroring the fire’s expansion and resource deployment.
Official source description: 10 Miles NW from Stehekin, WA
Active; Backing; Flanking; Isolated Torching
Given the fire’s active behavior and limited containment, residents and visitors in the surrounding area should remain vigilant, follow official evacuation orders if issued, and stay informed through local authorities and the NIFC updates.
IRWIN ID: {DC4342D9-B479-44F1-906C-8ABD42E1F59C}
Discovered: Aug 14, 2026
Cause: Natural
Managing Agency: USFS
Est. Cost to Date: $5,764,284
Coordinates: 48.3467, -120.8307
Other wildfires that have recently been contained or dropped from official tracking in WA.
The SISI Fire has burned 3,993 acres as of September 23, 2026.
As of the latest update, the SISI Fire is 15% contained.
The official cause has been listed as: Natural.
The SISI Fire is burning in Chelan, WA.
Yes, as of the latest official update, the SISI Fire remains active.
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