Big Rock Fire, Idaho Falls, Idaho

True view Fire view

⟷

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

Location20 miles east of Idaho Falls, ID

CauseNatural

What's burningBrush (2 feet)

How it's behavingMinimalCreeping — Moves slowly, hugging the ground.Smoldering — Burning without flame, in the ground or in roots. Can flare up days later.

ComplexityType 2 IncidentOfficial scale from 5 to 1: a Type 1 is the most complex in the country.

JurisdictionBLM · Federal land

Cost so far$3.5 million

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

After burning across 2,142 acres over the course of 84 days, the natural-cause Big Rock Fire located 20 miles east of Idaho Falls in Jefferson County, Idaho, has officially ended. The fire exhibited an average daily growth of about 26 acres per day as it moved through 2-foot brush on federal land managed by the BLM. At its height, the Type 2 incident involved 3 personnel.

By the time firefighters achieved 100 percent containment and brought the incident to a close, suppression efforts accumulated a total cost of about $3.5 million, specifically 3,530,000 USD. During the final phases of the incident, fire behavior was characterized as minimal, creeping, and smoldering.

This event occurred within the region's typical fire season, which runs from June to October. On a broader scale, the wider landscape has seen 3,455,585 hectares burned so far in 2026, a figure that tracks 37% below the two-decade average.