The stream flow of the Little Missouri River at Camp Crook reached a record high when the water level peaked, according to real-time U.S. Geological Survey stream-gage data.

The water level peaked at 19.42 feet on Tuesday, about seven feet above the National Weather Service designated flood stage of 12 feet.

"This event only had a 0.2 percent chance of occurring, making it a 500-year event," said Joyce Williamson, a USGS hydrologist. "This doesn't mean that the next comparable flood will be in 500 years, just that there is a 0.2 percent chance of this level of flooding to occur. Multiple 500-year events can occur in a short time frame and then not again for a very long time."

By 10:30 a.m. Wednesday, the water had gone down to 18.47 feet, according to Michael Carlson, Belle Fourche Area Engineer with the South Dakota Department of Transportation.