Clay County comprises the Spencer, IA Micropolitan Statistical Area.

The first newspaper in Clay County was the Peterson Patriot which started publication in 1880.

[4] Clay County is home to the large Barringer Slough wetland.

[12] As of the census[13] of 2000, there were 17,372 people, 7,259 households, and 4,776 families residing in the county.

29.80% of all households were made up of individuals, and 13.70% had someone living alone who was 65 years of age or older.

[citation needed] At one point Great Lakes Airlines was headquartered in Summit Township, Clay County.

Exceptions to this include Bull Moose candidate & former president Theodore Roosevelt winning a majority in 1912, the longest Democratic streak in its history when Franklin D. Roosevelt & Harry S. Truman were on the ballot from 1932 to 1948, Lyndon B. Johnson winning in a landslide statewide & nationally in 1964, Michael Dukakis getting a huge boost statewide thanks to the Midwest farm crisis in 1988, & Bill Clinton benefiting from Ross Perot gaining significant minorities of the county's vote in 1992 & 1996.

The level of Republican support has increased significantly in recent years, with Hillary Clinton posting the worst performance since 1952 when Adlai Stevenson won an identical percentage of the county's votes at 26.1%.