Grass fire beside Fort Peck Dam powerhouse cuts power near Glasgow

On the night of 3 September 2026, a grass fire broke out beside the powerhouse at Fort Peck Dam on the Missouri River in Montana. Local emergency services said a failed transformer knocked a live power line to the ground and the grass caught. As reported, the operating agency's own statement described a large grass fire outside the building and did not use the word transformer. Power was lost to 3,157 NorthWestern Energy customers in the Glasgow area from about 10:30 p.m. until about 12:17 a.m. Three hydroelectric units that were running were taken offline to protect the machinery and the grid and stayed offline for roughly four hours while checks were made. Local fire crews and project staff put the grass fire out. The fire stayed outside the powerhouse. Nobody on site was hurt, and staff on duty were evacuated. The units were later reported back in operation. No public cause for the failure had been given.

Local emergency services described a transformer failure that brought down a live line and ignited grass beside high-voltage equipment. The cause of that failure had not been published. The Army Corps of Engineers and the Western Area Power Administration were reported to be investigating. Grass close to the switchyard was noted as a poor combination with high-voltage gear, whichever way the sequence ran.

1. Taking generating units offline during a switchyard or powerhouse-yard fault can protect the machines and the wider grid.
2. Coordination between plant staff, local fire services and transmission crews can restore customers before the generators themselves return.
3. Vegetation hard against high-voltage equipment can turn an electrical fault into a grass fire, so clearance around switchyards matters.

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