"This fire is notable for its early detection and relatively small size of 10 acres, but the lack of containment data means its future trajectory is uncertain. The undetermined cause highlights the need for ongoing investigation."
The Bear Mountain wildfire was discovered on August 28, 2026, near Sweet Grass County, Montana, and has burned an estimated 10 acres as of the latest update on September 22, 2026. The cause of the fire remains undetermined, and no jurisdictional agency has been identified. Current fire behavior, weather conditions, and containment status are not reported, so no specific details are available regarding how the fire is evolving. The incident remains active, but no additional growth or containment information has been provided since the initial report.
Good air quality. Outdoor activity is generally safe near this incident.
Nearest reporting station: Lewistown. Source: AirNow.gov (EPA).
General wildfire safety guidance applies: stay informed about local fire conditions, follow any official advisories, and be prepared to evacuate if instructed.
IRWIN ID: {D6DB740C-34D9-47D7-AA8B-FE94C49EF334}
Discovered: Aug 28, 2026
Cause: Undetermined
Coordinates: 46.2048, -109.7308
Other wildfires that have recently been contained or dropped from official tracking in MT.
The Bear Mountain Fire has burned 10 acres as of September 22, 2026.
The Bear Mountain Fire has not yet reached any official containment.
The official cause has been listed as: Undetermined.
The Bear Mountain Fire is burning in Sweet Grass, MT.
Yes, as of the latest official update, the Bear Mountain Fire remains active.
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