Keystone in Pennington County, South Dakota — The American Midwest (Upper Plains)
40th Anniversary of "The Flood"
Photographed by William Fischer, Jr., September 22, 2026
1. 40th Anniversary of "The Flood" Marker
On June 9, 1972 the towns of Rapid City and Keystone were decimated by a flash flood which claimed a total of 238 lives. Rain began in late afternoon and continued through the night, increasing in intensity, with sky-splitting lightning. Within four hours, up to 16 inches of rain fell, causing the dam in Rapid City to give way, sucking the lake dry. In Keystone, Battle and Grizzly Creeks overflowed their banks, sweeping away campers, buildings, and automobiles. The village had voted for incorporation just days before, fortunately allowing them to receive disaster aid and rebuild.
Many heroes saved lives by putting their own in jeopardy. Among the organizations who volunteered in Keystone were residents of Keystone, Boy Scouts, National Guard, 1st Responders, Firefighters, the Men[n]onites, the Jaycees, business owners and other towns.
[Photos of the flood's aftermath]
Erected by Keystone Area Historical Society.
Topics. This historical marker is listed in these topic lists: Disasters • Environment • Waterways & Vessels. A significant historical date for this entry is June 9, 1972.
Location. 43° 53.603′ N, 103° 25.492′ W.
this page online
Regionally, this marker is in West River, in the Badlands, and in Greater Rapid City. It is also in the American Black Hills, in the Lewis & Clark Corridor, on the prairies, and on the Northern Plains. Globally, it is in North America, the Western Hemisphere, the Western World, and the Anglosphere. Historically, it finds itself in what was once Rupert’s Land and also the Louisiana Purchase.
Other nearby markers. At least 8 other markers are within walking distance of this marker: The Black Hills Central Railroad (about 300 feet away, measured in a direct line); 1972 Battle Creek Flood (about 300 feet away); Carrie Ingalls Swanzey (about 300 feet away); Gutzon Borglum (approx. 0.2 miles away); The Seated Lincoln (approx. 0.2 miles away); Dr. E. L. Trudeau (approx. 0.2 miles away); William Jennings Bryan
Photographed by William Fischer, Jr., September 22, 2026
2. 40th Anniversary of "The Flood" Marker
Battle Creek in background
Also see . . . The Black Hills-Rapid City Flood of June 9-10, 1972 (USGS). (Submitted on October 4, 2026, by William Fischer, Jr. of Reynoldsburg, Ohio.)
Credits. This page was last revised on October 4, 2026. It was originally submitted on October 4, 2026, by William Fischer, Jr. of Reynoldsburg, Ohio. This page has been viewed 3 times since then. Photos: 1, 2. submitted on October 4, 2026, by William Fischer, Jr. of Reynoldsburg, Ohio.
