44770 Madison Earthquake Area
The 1959 Yellowstone earthquake is also known as the Hebgen Lake earthquake. It was a powerful earthquake that occurred on August 17, 1959 at 11:37 pm (MST) in southwestern Montana. The earthquake was registered at magnitude 7.3 – 7.5 on the Richter scale. The quake caused a huge landslide that caused over 28 fatalities and left $11 million (1959 USD, $74.1 million 2006 USD) in damage. The quake-induced landslide blocked the flow of the Madison River resulting in the creation of Quake Lake. Effects of the earthquake were also felt in Idaho and Wyoming.
The 1959 quake was the strongest and deadliest earthquake to hit Montana since the 1935-36 Helena earthquakes left 4 people dead. It also caused one of the worst landslides in the history of the Northwestern United States.