[7] Hardin and its cemetery were affected by the Great Flood of 1993, due to their location near the Missouri River.

On July 12, 1993 a levee protecting the town of Hardin broke, flooding the city and the cemetery.

Some were still inside their vaults or caskets (thus helping making identification easier), while others were scattered in the open.

Since DNA testing was still in its infancy, bodies and bones had to be identified by the rate of decay, sex, age range, dental records and family recollections.

The unidentified bodies were reburied in a mass grave in part of a 9.5 acre plot of land that was purchased by the cemetery after the 1993 flood.

The unidentified were marked with a headstone listing them as unknown and a number, so in case the bodies were to be disturbed again by another flood or if authorities wanted to try to identify them with newer technology or DNA testing in the future.

Part of the newly acquired acre of land was also used to display the recovered headstones of those whose bodies were not identified.

They today function as a Cenotaph for the unidentified bodies so living family members can still pay respects.

In 1995, a second memorial was added near the mass grave displaying the names, birth and death years of the displaced bodies that could not be identified.

[8][9][10] According to the United States Census Bureau, the city has a total area of 0.64 square miles (1.66 km2), all land.