[2] Its eastern boundary abuts the west lines of the states of Nebraska and South Dakota.

[3] The county was named for the Niobrara River, which rises near Lusk.

[5] In comparison to the state of Rhode Island, the county has more than twice the land area, with approximately 1/500 of the population.

[6] As of the 2000 United States Census,[10] of 2000, there were 2,407 people, 1,011 households, and 679 families in the county.

29.50% of all households were made up of individuals, and 14.10% had someone living alone who was 65 years of age or older.

As of the 2010 United States Census, there were 2,484 people, 1,069 households, and 659 families in the county.

[11] In terms of ancestry, 41.5% were German, 19.0% were English, 17.7% were Irish, 6.6% were Swedish, and 3.0% were American.

No Democratic presidential candidate has won Niobrara County since Franklin D. Roosevelt beat Alf Landon in 1936 by thirty-eight votes, and none since Lyndon Johnson in 1964 has attained thirty percent of the county's vote.

[16] The facility was operated by the Wyoming Board of Charities and Reform until that agency was dissolved as a result of a state constitutional amendment passed in November 1990.