Accordingly, the county government was organized on November 28, with Carson as the seat.

[3][4][5] The Heart River flows eastward through the upper part of Grant County, and Cedar Creek flows east-northeastward along the county's southern boundary line.

[6] The terrain slopes to the east and south; its highest point is a rise near its southwestern corner, at 2,680 ft (820 m) ASL.

[8] Lake Tschida, a Bureau of Reclamation reservoir and recreation area on the Heart River, is the county's largest body of water.

[9] The southwestern corner of North Dakota observes Mountain Time (Adams, Billings, Bowman, Golden Valley, Grant, Hettinger, Slope, and Stark counties).

In terms of ancestry, 66.6% were German, 14.0% were Norwegian, 12.5% were Russian, 5.9% were Irish, 5.5% were English, and 2.2% were American.

In no national election since 1936 has the county selected the Democratic Party candidate.