Mercer county is located in west central North Dakota. The county population on July 1, 1999, was 9,210, a decrease of 598 over the 1990 census.
The county's northern and northeastern boundaries are defined by Lake Sakakawea and the Missouri River which also provide the bulk of the area's recreational opportunities. Lake Sakakawea State Park, located near Garrison Dam at Pick City and the Knife River Indian Village NHS, located on the river near Stanton, the county seat, provide the part of the "things to do and see" list for Mercer county.