Slough Grass Fire, Lame Deer, Montana

True view Fire view

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True view (left): as the eye sees it.
Fire view (right): infrared (SWIR), sees through smoke and brings out the heat.

🟢 green = vegetation
🟤 brown = already burned
🟠 orange = fire right now

Drag to compare: normal photo on the left, heat brought out on the right.

Green: vegetationBrown: already burnedOrange: fire right nowSentinel-2 · Copernicus

Key facts

Source: NIFC

Location8 miles northwest of Colstrip, MT

CauseNatural

What's burningTimber (Grass and Understory)

How it's behavingModerate, Uphill RunsSpotting — Wind carries embers through the air and starts new fires ahead of the front: that is how a fire jumps a road or a firebreak.

ComplexityType 3 IncidentOfficial scale from 5 to 1: a Type 1 is the most complex in the country.

JurisdictionDNRC · State land

Cost so far$150,000

Glossary: what each term means

Minimal

Barely moving. Low, thin smoke.

Smoldering

Burning without flame, in the ground or in roots. Can flare up days later.

Creeping

Moves slowly, hugging the ground.

Moderate

Spreads with low, steady flames.

Active

Spreading evenly and steadily, with visible flame.

Extreme

Fast and unpredictable.

Running

Runs along the ground much faster than a person walks.

Flanking

Grows along the sides, not head-on.

Backing

Moves against the wind or downhill, which makes it slower.

Crowning

Climbs into the treetops and jumps crown to crown. It can't be attacked from the ground.

Short Crown Runs

Climbs into the crowns in bursts and drops back down.

Torching

Whole trees flaring up like torches.

Isolated Torching

Single scattered trees flaring up whole, like torches.

Group Torching

Whole clumps of trees flaring at once.

Spotting

Wind carries embers through the air and starts new fires ahead of the front: that is how a fire jumps a road or a firebreak.

Wind Driven Runs

The wind pushes it in long runs in one direction.

The ones marked ● are the behaviors that make a fire harder to stop. They are not a warning or an instruction: they are the description written by the agency in charge. For decisions, always follow your emergency services.

The story so far

The Slough Grass Fire near Lame Deer, Montana, in Rosebud County, burned for 91 days after starting on August 6, 2026, driven by natural causes through timber, grass, and understory on state land overseen by the DNRC. Situated 8 miles northwest of Colstrip, the Type 3 incident ultimately consumed 5,465 acres with an average daily growth of approximately 60 acres per day.

During its 91-day duration, the fire exhibited moderate behavior, uphill runs, and spotting. A response team of 69 personnel worked to manage the incident, bringing containment to 10 percent before the fire ended. Total suppression costs reached about $150,000.

The broader fire season in the region typically spans from June to October. Across the country, 2026 has seen 3,495,644 hectares burned so far, marking a figure that is 36% below the two-decade average.