The strongest and deadliest earthquake in Montana's recorded history, it triggered a massive landslide that created Quake Lake and killed over 28 people.
Key Facts
- Magnitude
- 7.2 Mw
- Fatalities
- Over 28
- Property damage
- $11 million (1959) USD
- Time of occurrence
- 11:37 pm MST, August 17, 1959
- New lake formed
- Quake Lake (Madison River blocked)
- Worst landslides in NW US since
- 1927
By the Numbers
Location
Cause → Event → Consequence
A major seismic event struck along fault lines in the Madison Range of southwestern Montana near Hebgen Lake. The region sits within the tectonically active northern Rocky Mountains, where accumulated stress along faults periodically releases in large earthquakes.
On August 17, 1959, at 11:37 pm MST, a magnitude 7.2 earthquake struck near Hebgen Lake in southwestern Montana. It triggered a massive landslide and was felt as far away as Puerto Rico and Hawaii, making it the strongest earthquake ever recorded in Montana.
The landslide blocked the Madison River, forming a new body of water named Quake Lake. More than 28 people died and approximately $11 million in damages were recorded. The event also represented the worst landslide disaster in the northwestern United States since 1927.
Human Cost
Each dot represents approximately 10,000 deaths. Total estimated: 28 (earthquake)