Fort Pierre is located in Stanley County (of which it is the county seat) just southwest of Pierre along US 83 on the banks of the Missouri River near the Bad River and Lake Oahe, in Great Lakes Region.
Just south of the city is Fort Pierre National Grasslands, a 116,000-acre block of public land made up of rolling hills and prairie and serving as home to antelope, mule deer, prairie dogs, prairie chickens and myriad waterfowl. Many small, scattered dams offer fishing.
The population estimate for July 1, 1998 was 2,188, an increase of 334 since 1990.