March 28th, 1964 Southwestern South Dakota experienced tremors from an earthquake registering 5.1 on the Richter scale. The quake was centered near Merriman, Nebraska.
Four days earlier on March, 24th, the staff at Wind Cave National Park reported tremors that lasted just a few seconds. The epicenter of that quake was thought to be in eastern Wyoming.
Before seismographs and the Richter scale were introduced in 1935, earthquakes were measured by intensity, or how much damage was caused on the surface. Since 1935, the Richter scale has given geologists a much clearer depiction of the magnitude of an earthquake.
The most significant quake in the upper plains was in November 1877. That quake was felt across most of Nebraska and portions of Iowa, Kansas, Missouri, and the Dakotas. That quake lasted about 40 seconds, and more significant damage was reported in Lincoln, Columbus, and Omaha, Nebraska.
The 1964 quake affected about 90,000 square miles of western Nebraska, South Dakota, and the border areas of Montana and Wyoming. It caused many cracks in roadways, some steep banks along the Niobrara River tumbled, plaster fell off ceilings, and goods were damaged in homes and stores.
Earthquakes are not uncommon along several fault lines that extend throughout the Midwest, but most are much smaller in scale than the quake that hit Southwestern South Dakota March 28th, 1964.
Production help thanks to Doctor Brad Tennant, Professor of History at Presentation College.