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Idaho: Risks & Trends

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Same standard as every other page on this site: every figure below is independently sourced, and figures that vary across sources, or measure genuinely different things, are flagged as such rather than collapsed into one number that looks more precise than the underlying data actually supports.

The 1910 Big Burn

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Dates August 20-23, 1910
Area burned ~3 million acres across northern Idaho and western Montana
Deaths 87 total, 78 of them firefighters
Peak winds Up to 70 mph, driving separate fires into one massive firestorm
Firefighters deployed ~4,000 civilian firefighters plus ~4,000 U.S. Army troops
Long-term policy effect Prompted the U.S. Forest Service's aggressive nationwide fire-suppression policy for most of the 20th century

A policy legacy worth understanding

The Big Burn’s aftermath led directly to a “put every fire out immediately” national policy. That policy is now understood to have allowed forests to grow denser with unburned fuel over decades, contributing to the larger, more intense wildfires seen across the Western U.S. in recent years, including the fires covered on California and Oregon’s pages. The 1910 fire didn’t just kill 87 people; it shaped the wildfire risk every Western state faces today.

The 1976 Teton Dam failure

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Date June 5, 1976, during the reservoir's first filling
Peak flow released 1,000,000+ cubic feet per second
Time to fully drain the reservoir ~6 hours
Deaths 11
Homes destroyed 733 (3,000+ more damaged)
Businesses destroyed 250
Livestock lost 13,000-20,000
Damage estimate $400 million (initial Bureau of Reclamation estimate) to $2 billion (broader total-loss estimates)
Towns most affected Sugar City, Rexburg, Wilford

Why the damage figures vary so widely

The $400 million figure reflects an early, narrower federal liability estimate; the $2 billion figure reflects broader total economic loss across the flooded region. Both numbers appear regularly in sources on this event; presenting the range rather than picking one keeps faith with what the underlying estimates actually measure.

Sources