Ninety-eight days into the trip, Sgt. Floyd became violently ill with what Lewis & Clark called "beliose chorlick," bilious colic. Modern doctors say he died of appendicitis. In 1804, there was no cure for appendicitis. If you got it, you died. He died the next day, on August 20, 1804.

They buried him on the top of a bluff overlooking the river in a rough coffin like this one shown in a diorama at the Interpretative Center.