August 8, 2002 Shelf Cloud
Several severe thunderstorms moved through the Black Hills on August 8th, 2002. Flash flooding also occurred in Deadwood, SD, which resulted in a large flow of mud and ash from the Grizzly Gulch fire that occurred earlier this summer.
The image below depicts a shelf cloud ahead of a severe thunderstorm that rolled over the National Weather Service office in Rapid City, SD.