The county's eastern border is the Texas state line.

[3] As of the 2000 census,[9] there were 18,018 people, 6,639 households, and 4,541 families living in the county.

24.70% of all households were made up of individuals, and 9.10% had someone living alone who was 65 years of age or older.

As of the 2010 census, there were 19,846 people, 7,299 households, and 4,671 families living in the county.

[13] The Roosevelt County clerk and deputy clerk resigned in late 2013 after the New Mexico Supreme Court ruled that all counties in the state must license same-sex marriages.

County Manager Bill Cathey said they had resolved to quit "rather than be associated with that," according to the Associated Press.

It has not voted for a Democratic presidential candidate since Lyndon B. Johnson in 1964.

However, the county is located in the New Mexico's 3rd congressional district, represented by Democrat Teresa Leger Fernandez.