[3] In the Nebraska license plate system, Sheridan County is represented by the prefix 61 (it had the sixty-first-largest number of vehicles registered in the state when the license plate system was established in 1922).

Sheridan County lies on the north line of Nebraska.

The terrain consists of arid rolling hills, dotted with small lakes in the eastern and southern parts of the county.

As of the 2000 United States Census,[15] there were 6,198 people, 2,549 households, and 1,728 families in the county.

29.60% of all households were made up of individuals, and 16.30% had someone living alone who was 65 years of age or older.

Sheridan County voters have traditionally voted Republican; every national election since 1940 has seen Sheridan County choose the Republican Party presidential candidate.